An analogy: A king says to his wife: "Bedeck yourself with all of your jewels so that you be desirable to me." Thus, the Holy One Blessed be He said to Israel. "Be distinctive in mitzvoth, so that you be desirable to Me." And thus is it written (Song of Songs 6:4) "Beautiful are you My beloved, as Tirtzah" — You are beautiful when you make yourself desirable ("retzuya" [like 'Tirtzah']) to Me (through mitzvoth)."
(Devarim 7:12) "And it shall be if you hearken to these judgments": (7:1) "When the L-rd your G-d brings you to the land to inherit it, etc.": This section was stated to Israel at the exodus from Egypt. For they said: Perhaps we will not enter a land as beautiful as this, whereupon the Holy One Blessed be He said to them: The land that you are coming to inherit is superior to it.