In this week's parasha, Naso, we are compounded with many different topics. One of such topics is Birkat Kohanim, the blessing which the Kohanim bless Bnei Yisrael on a daily basis. The actual verses are written in parashat Naso, perek 6 verses 22-27:
22 The LORD said to Moses,
23 "Tell Aaron and his sons, 'This is how you are to bless the Israelites. Say to them:
24 " ' "The LORD bless you and keep you;
25 the LORD make his face shine upon you and be gracious to you;
26 the LORD turn his face toward you and give you peace." '
27 "So they will put my name on the Israelites, and I will bless them."
Only the three middle verses are stated as a blessing by the Kohanim. The first two verses serve as the instruction from Hashem to command Moshe to tell Aharon and his sons about their obligation to bless Bnei Yisrael. What does the final verse serve as?
In the final verse Hashem tell Moshe that Aharon and his descendants must place the name of Hashem on Bnei Yisrael and then Hashem will bless them. Some rabbis explain that the "them" is referring back to the Kohanim, meaning, if the Kohanim do as Hashem commands, the Kohanim themselves will receive a blessing.
However, others explain that this word is referring to Bnei Yisrael. They explain that once the Kohanim use the name of Hashem to bless Bnei Yisrael, Hashem will turn and actually bless the nation.
Why is it that only with the name of Hashem will the blessing take effect?
Hashem guarantees the blessing when his name is used, because it is not enough for the Kohanim or even regular people to bless the nation. We are limited in our understanding of what we actually need. Sometimes a person may pray day and night to get a job that he thinks will be great for him. Little does he know, when his prayer goes "unanswered" – he was actually saved from more strife and problems than he ever thought about. Hashem answered the prayer, and the answer was no. Same here. When the name of Hashem is used, Hashem agrees that through His infinite knowledge, the blessing will be able to be an accurate reflection of what a person truly needs and not what they believe they need.