Or HaChaim on Exodus 34:11/אור החיים על שמות ל״ד:י״א

1 שמר לך, "Observe for yourself, etc.!" How does the term "observe" apply to the subject matter of this verse? If the Torah refers to the commandment G'd is about to reveal as something Moses is to "observe" as Rabbi Abraham ibn Ezra suggests, why would G'd select this commandment of not concluding a covenant with the seven Canaanite nations rather than any other of the many commandments as something for Moses to be very careful about? After all, Moses had already been told that it was not he who would conquer these nations What point was there in warning him specifically not to conclude such a covenant?

2Perhaps there is a lesson here about how true repentance works. Seeing the Israelites had become guilty of worshiping an idol, the תקון, rehabilitation, for such a sin required that they destroy everything even remotely connected with idolatry if they wanted to attain complete atonement for their sin. This required that they cultivate a strong abhorrence for all forms of idolatry starting already now, long before they would displace the idolatrous Canaanites and destroy any vestiges of idol worship the Canaanites had been guilty of. The verb שמר may perhaps be understood in the sense that Jacob used it when he heard Joseph's dream with the sun, the moon, and the eleven stars bowing down to him. At that time (Genesis 37,11), Jacob had begun to look forward to the way this dream would become fulfilled. The Israelites (including Moses) were now meant to look forward to the time when they could carry out the commandment G'd was about to give them.

3Alternatively, G'd implied that as long as the Israelites had not become guilty of making a molten image He would not have bothered to command them to keep a physical and cultural distance from the Gentile nations and their abominations. Seeing they themselves had become victims of the impulse to worship an idol, G'd now had to give the people this law in order to ensure that they would not again be tempted to succumb to idolatry. The words שמר לך, are a reminder that the law was due to something the Israelites themselves had done.

4A moral-ethical approach sees in the word לך "for yourself" a reference to Moses; G'd hinted to Moses that the words: "I am going to drive out before you the nations, etc." are not a reference to what would happpen in the immediate future, but refer to the distant future, to messianic times. It corresponds to the statement of our sages in Bamidbar Rabbah 19,13 which describes the Jews (the generation which perished in the desert) as saying that: "the same Moses who has redeemed us from Egypt will redeem us in the future." G'd told Moses to be looking forward to that time, i.e. שמר לך. You may find support for this interpretation when you consider that the promise contained in the line "I will drive out before you, etc.," has never been fulfilled during the time the Israelites travelled in the desert.