The L-rd bless thee and keep thee (Num. 6:24)
The Priestly blessing is said in the singular because it is primarily the blessing of unity that the Jews need. (O'lot Efraim)
The princes of Israel brought their offerings, the heads of their fathers' houses... they brought their offerings before the L-rd (Num. 7:2.3)
Twelve times the Torah repeats this phrase, detailing the identical offerings brought by each of the princes of the twelve tribes. Why the repetition? These offerings were the same only externally; in actuality, each prince brought his offering in a different manner, a manner corresponding to the tribe's spiritual source in Heaven. (Likutei Torah)
And they shall confess their sin which they have committed (Num. 5:7)
Why is the commandment to confess one's sin, the first step and foundation on the path to repentance, mentioned here, where the Torah speaks about robbery? Because any sin a person may commit has an element of robbery in it. G-d gives a person life and strength, in order that he use these gifts to perform His will. If one takes these gifts and uses them to defy G-d, he is misusing and "stealing" the property of his Creator. (Chidushei HaRim)
May G-d cause His face to shine upon you (Num. 6:22)
G-d's "face" symbolizes His love, goodwill, and closeness to us. "May G-d cause His face to shine upon you" means that the innermost part of G-d's Divine Will should shine upon and illuminate the Jewish people and that which has its source in holiness. Of course, everything in this world comes from G-d, and even things which are not holy derive their sustenance and life-force from G-d too, but this is an inferior and external sustenance. To what can it be likened? A king makes an elaborate party and invites all his highest ministers and officials to partake of the meal. Naturally, his servants and maids, and even the dogs, will eventually benefit from the leftovers, but this was not the king's intent when he made the feast. The dignitaries are influenced by the king's "innermost" will, and the servants, maids and animals receive only the "external" benefits. (Kuntres U'Maayan)
Reprinted from the Nasso 5762/2002 edition of L’Chaim