Which was Moses’ greatest achievement? Taking the Jews out of Egypt? Splitting the Red Sea? Receiving the Torah from G-d and transmitting it to humanity? If we are to judge by the Torah’s final summation of his life, Moses’ greatest deed was his breaking the Two Tablets of the Covenant, inscribed with the Ten Commandments by the very hand of G-d!
In the closing verses of Deuteronomy we read:
Moses, the servant of G-d, died there in the land of Moab… And there arose not since a prophet in Israel like Moses, whom G-d knew face to face; [who performed] all the signs and wonders which G-d sent [Moses] to do in the land of Egypt… [who equaled] that mighty hand, those great fearsome deeds, [and that] which Moses did before the eyes of all Israel.
Rashi,  in his commentary on Torah, interprets the last verse as follows:
That mighty hand—“that he received in his hands the Torah, contained in the tablets.”
Those great fearsome deeds—“The miracles and feats he performed in ‘the great and fearsome desert.’  ”
[that] which Moses did before the eyes of all Israel— “that his heart emboldened him to break the tablets before their eyes, as it is written, ‘[and I took hold of the two tablets and threw them from my two hands] and I broke them before your eyes.’  G-d’s opinion then concurred with his opinion, as it is written, ‘[… the first tablets,] which you broke’  —I affirm your strength for having broken them.”
(The Hebrew word asher (“which”) can also be pronounced ishur, which means “to affirm” and “to praise.” Thus, G-d’s words to Moses, “… the first tablets, which you broke” can also be understood as: “I affirm your having broken them” or “Thank you (yishar kochacha) for breaking them.”) 
The breaking of the tablets was a most tragic event, signifying a breakdown of the special relationship entered into by G-d and Israel at Sinai—a relationship embodied by the Torah and encapsulated in the Ten Commandments that G-d inscribed on the tablets. Indeed, our sages see the breaking of the tablets as the source of all subsequent tragedies of Jewish history: “Had the first tablets not been broken,” declares the Talmud, “no nation could ever had subjugated the Jewish people.” Another indication of how grievous an event this was is its use as a prototype for bereavement and loss: “The death of the righteous,” say our sages, “is as tragic to the Almighty as the day on which the tablets were broken.” 
And yet, G-d endorsed Moses’ unilateral decision to break the tablets. Obviously, then, Moses had just cause to do so. But why does this culminate the Torah’s litany of his greatest achievements? With so many positive accomplishments to Moses’ credit, why accentuate so negative an event, no matter how justified and necessary?
The Talmud tells us that “everything goes by the ending.”  This would mean that by culminating Moses’ praises with the mention of his breaking the tablets, the Torah is implying that this was his greatest virtue—greater than his being “the servant of G-d” for 120 years; greater than his being the only human being with whom G-d communicated face to face, “manifestly,  not by allegory”; greater than the “signs and wonders” he performed in Egypt, birthing a nation and leading them to freedom; greater than his possessing “the mighty hand” which received the Torah from G-d; greater than his sustaining, protecting and governing a querulous 3,000,000 souls in “the great and fearsome desert” for forty years!
Furthermore, the words “which Moses did before the eyes of all Israel” (which Rashi understands as a reference to Moses’ breaking of the tablets) are not only the Torah’s last word on Moses—they also are the closing words of the Torah itself. This means that the Torah climaxes with an account of its own devastation!
The Wayward Bride
What prompted Moses’ heart to “embolden him to break the tablets”?
The Jewish people had worshipped the Golden Calf, violating their covenant with G-d documented in the tablets. Moses thus found himself in the position of having to choose between the preservation of the Torah or the preservation of Israel, as the Midrash illustrates with the following metaphor:
Once there was a king who went off on a distant journey and left his bride with her maidservants. Because of the [promiscuity of the] maidservants, rumors began circulating about the king’s bride. The king heard of this and wished to kill her. The bride’s guardian heard of this, so he went ahead and tore up her marriage contract, saying: “Should the king say, `My wife did such and such,’ we shall say to him, `She’s not your wife yet.’ “ The king subsequently investigated and found that there was nothing promiscuous in his bride’s behavior, that only the maidservants were corrupt, and was reconciled to her. Said the bride’s guardian to the king: “Sir, make her another marriage contract, for the first one was torn up.” Said the king to him: “You tore it up, so you supply the paper and I shall write on it with my hand” … Thus, when G-d forgave [the Jewish people], He said to Moses: “Carve,  yourself, two tablets of stone [like the first ones, and I shall write on these tablets what was on the first tablets, which you broke].” 
G-d, explains the Midrash, is the king, Israel His bride, the erev rav (the “mixed multitude” who had joined the Jewish people at the Exodus and were responsible for the making of the Golden Calf) her corrupt maids, Moses her guardian, and the Torah the wedding contract. When G-d wished to destroy Israel because of their involvement in the worship of the Golden Calf, Moses smashed the tablets, thereby dissolving the marriage-bond that they had allegedly violated and leaving G-d no grounds on which to punish His bride’s “unfaithfulness.”
And this the Torah considers to be Moses’ highest virtue: his unequivocal loyalty to the Jewish people, a loyalty even greater than his loyalty to the Torah.
When the very existence of the Jewish people is threatened, Moses is prepared to tear up the wedding contract in order to save the bride. No one is more deeply identified with the Torah than Moses. “Remember the Torah of Moses My servant,”  enjoins the prophet Malachi. The Torah of Moses? Is it not G-d’s Torah? Explains the Midrash: because Moses gave his life for the Torah, it is called by his name.  With no one was it more true that the breaking of the tablets is akin to “the death of the righteous”: in smashing the tablets, Moses stood to destroy everything he was and stood for. And yet, when the Jewish people are in jeopardy–or even a small minority of the Jewish people, corrupted by the fringe element oferev rav–Moses does not hesitate to break the tablets.
When the Jewish people are in jeopardy, Moses does not consult anyone. He does not even consult G-d. When Moses must choose between Torah and Israel, his devotion to Israel supersedes all—including that which defines the very essence of his own being: his divine mission and his relationship with the Almighty.
Indeed, Moses’ breaking of the tablets is the greatest deed of his life. In everything else he did, he was acting on a clear mandate from G-d: G-d instructed and empowered him to take the Jews out of Egypt, split the Red Sea and transmit His wisdom and will to humanity. Always it was G-d’s desire that he followed; here, it was “his own opinion,” with which the divine opinion subsequently concurred.
In breaking the tablets, Moses was acting on his own, contrary to his divine mission to deliver G-d’s Torah to the world. In breaking the tablets, Moses, who could not presume that G-d was to replace the first tablets with a second pair, was eradicating his very being, his very raison d’etre, for the sake of his people.
And Moses did not go off to a side to carry out the most painful and potentially self-destructive act of his life. He broke the tablets “before the eyes of all Israel,” a fact which the Torah repeatedly emphasizes, and then reiterates in its concluding words. For Moses wished to demonstrate to all of Israel, and to all generations to come, the duty of a leader of the Jewish people: to recognize that “Israel precedes all in the mind of G-d,” including even the Torah.  To be prepared to not only sacrifice his physical life for his flock, but also his very soul and spiritual essence.
First Between Firsts
Not only does the Torah record that G-d endorsed Moses’ breaking of the Tablets; not only does it proclaim that Moses’ greatest deed was his placing the preservation of Israel above the integrity of the “wedding contract”; it also chooses to make this its own culminating message. With its closing words the Torah establishes that it sees its own existence as secondary to the existence of the people of Israel.
The Midrash says it thus:
Two things preceded G-d’s creation of the world: Torah and Israel. Still, I do not know which preceded which. But when Torah states `Speak to the Children of Israel…,’ `Command the Children of Israel…,’ etc., I know that Israel preceded all. 
In other words, since the purpose of G-d’s creation of the universe is that Israel might implement His will as outlined in the Torah, the concepts of “Israel” and “Torah” both precede the concept of a “world” in the Creator’s “mind.” Yet which is the more deeply rooted idea within the divine consciousness, Torah or Israel? Does Israel exist so that the Torah be implemented, or does the Torah exist to serve the Jew in the fulfillment of his mission and the realization of his relationship with G-d?
Says the Midrash: if the Torah describes itself as a communication to Israel, this presumes the concept of Israel as primary to that of Torah. Without Jews to implement it, there cannot be a Torah, since the very idea of a Torah was conceived by the divine mind as a tool to facilitate the bond between G-d and His people.
Hence, when the Torah speaks of the shattering of the Tablets, it speaks not of its own destruction, but, ultimately, of its preservation: if the breaking of the Tablets saved Israel from extinction, than it also saved the Torah from extinction, since the very concept of a “Torah” is dependent upon the existence of a Jewish people. 
Pressing For Redemption
Moses’ self-negating devotion to his people characterized his leadership from its inception. When G-d first appeared to Moses in the burning bush and commanded him to take the Jewish people out of Egypt, Moses refused. For seven days and nights Moses argued with G-d. “Send who You will send,”  Moses pleaded. Do not send me
“G-d’s anger raged against Moses,” the Torah tells us.  Understandably so: the Jewish people are languishing under the Egyptian whip, and G-d’s chosen redeemer is refusing his commission. Still Moses argued with G-d to “send who You will send” instead of himself. Why did Moses refuse to go? Was it his humility? True, the Torah attests that “Moses was the most humble man on the face of the earth.”  But surely Moses was not one to allow his humility to interfere with the salvation of his brethren.
Our sages explain that Moses knew that he would not merit to bring Israel into the Holy Land and thereby achieve the ultimate redemption of his people.  He knew that Israel would again be exiled, would again suffer the physical and spiritual oppression of galut. So Moses refused to go. Do not send me, he pleaded, send now whom You will send in the end of days. If the time for Israel’s redemption has come, send Moshiach, through whom You will effect the complete and eternal redemption.  For seven days and nights Moses contested G-d’s script for history, prepared to incur G-d’s wrath upon himself for the sake of his people.
Nor did Moses ever accept the decree of galut. After assuming, by force of the divine command, the mission to take Israel out of Egypt, he embarked on a lifelong struggle to make this the final and ultimate redemption. To the very last day of his life, Moses beseeched G-d to allow him to lead Israel into the Holy Land, which would have settled Israel in their land, and G-d in Israel’s midst, for all eternity;  to his very last day he braved G-d’s anger in his endeavor to effect the ultimate redemption. In Moses’ own words: “I beseeched G-d… ‘Please, let me cross over and see the good land across the Jordan, the good mountain (Jerusalem) and the Levanon (the Holy Temple).’ And G-d grew angry with me for your sakes… and He said to Me: ‘Enough! Speak no more to Me of this matter…’ ” 
G-d said “Enough!” but Moses was not silenced. For Moses’ challenge of the divine plan did not end with his passing from physical life. The Zohar tells us that every Jewish soul has at its core a spark of Moses’ soul.  So every Jew who storms the gates of heaven clamoring for redemption continues Moses’ struggle against the decree of galut.
Editor’s note: The above is based on two talks delivered by the Rebbe, the first on Simchat Torah of 5747 (1986) and the second on Shabbat, the 9th of Av, 5751 (1991). The Rebbe wept profusely during the Simchat Torah address, describing Moses’ breaking of the tablets in a voice choked with tears.
 Rabbi Shlomo Yitzchaki (1040-1105), whose work is the most basic of biblical commentaries.
 Deuteronomy 8:15.
 Ibid., 9:17.
 Exodus 34:1.
 See Rashi on Talmud, Shabbat 87a.
 Talmud, Eruvin 54a.
 Jerusalem Talmud, Yuma 1:1.
 Talmud, Brachot 12a.
 See Numbers 12:6-8
 Exodus 34:1.
 Midrash Tanchuma, Ki Tisa 30; a slightly different version is cited by Rashi in his commentary on Exodus 34:1.
 Malachi 3:22.
 Midrash Rabba, Shmot 30:4.
 See Midrash quoted further on in this essay.
 Tana D’vei Eliyahu Rabba, chapter 14.
 Thus, the entire Torah is set aside to save a Jewish life. In the words of the Talmud, “Desecrate a single Shabbat over him, so that he may observe many subsequent Shabbatot” (Talmud, Shabbat 151b). Here, too, a “violation” of the Shabbat is seen as its ultimate preservation. On the other hand, “Israel, though he has transgressed, is still Israel” (Talmud,Sanhedrin 44a). The inherent bond between G-d and His people is realized through their observance of Torah, but is not dependent upon it; even when a Jew violates the Torah, G-d forbid, his identity as a Jew is unaffected. Thus we have the concept of teshuvah (“return”): also when a Jew has damaged his relationship with G-d as defined by Torah, he can supercede Torah’s definition of the relationship and reawaken it through the yearning, regret and resolve of teshuvah.
 Exodus 4:13.
 Ibid., 4:14.
 Numbers 12:3.
 See note 22
 Rashi on Exodus 4:13; Midrash Lekach Tov, ibid.
 “The deeds of Moses are eternal” (Talmud, Sotah 9a; thus themishkan, the sanctuary that Moses built in the desert, was never destroyed). If Moses would have settled the people of Israel in their land, there would have been no subsequent exiles (Megaleh Amukot, section 185; see Alshich and Or Hachaim commentaries on Deuteronomy 4:23).
 Deuteronomy 4:23-26.
 Tikkunei Zohar 69, pp. 112a and 114a; see Tanya ch. 44