Sifrei Bamidbar 39

(Bamidbar 6:22-23) "And the L-rd spoke to Moses, saying: Speak to Aaron and to his sons, saying: Thus shall you bless, etc.": Because the entire section deals with Cohanim, Aaron and his sons are brought into the context of "saying" (dibbur). For this is the rule: Wherever the "dibbur" is to the Cohanim, the action (of that section) is that of the Cohanim. Where the "dibbur" is to Israel as a whole, the action is that of Israel. Where the "dibbur" is to all men, the proselytes are to be included. "Thus shall you bless the children of Israel": in the holy tongue. — But perhaps any tongue is permitted. It is, therefore, written (Devarim 27:12) "These shall stand to bless the people." Just as there, in the holy tongue, so, here, in the holy tongue. R. Yehudah says: This (i.e., the above identity) is not needed, for wherever "aniyah" ("answering"), "amirah" ("saying") or "cachah" ("thus") is written, the holy tongue is intended. "Thus shall you bless the children of Israel" — standing. You say, standing; but perhaps either standing or not standing is permitted. It is, therefore, written "These shall stand to bless the people." It is written here "blessing" and there, "blessing." Just as "blessing" there is standing, so, "blessing" here. R. Nathan says: This (derivation) is not needed, for it is written (of the Cohanim, Devarim 10:8) "… to stand before the L-rd, to minister unto Him, and to bless His name." Blessing is likened to ministering. Just as ministering is standing, so, blessing. "Thus shall you bless the children of Israel": with raised hands. You say, with raised hands; but perhaps either with or without raised hands is permitted. It is, therefore, written (Vayikra 9:22) "And Aaron lifted his hands to the people and he blessed them." Just as there, with raised hands, so, here. R. Yonathan says: But perhaps just as there, Rosh Chodesh, offering, and the high-priest, so, here (these elements must obtain)! It is, therefore, written (Devarim 18:5) "For him (a Cohein) did the L-rd your G-d choose from all of your tribes to stand and minister in the name of the L-rd, he and his sons all of the days." His sons are likened to him. Just as he, with raised hands, so, his sons with raised hands. "Thus shall you bless the children of Israel": with the explicit name (the Tetragrammaton [yod-keh-vav-keh]). You say, with the Tetragrammaton. But, perhaps, only with an epithet. It is, therefore, written (Ibid. 27) "And they shall place My name on the children of Israel" — the name that is distinctive with Me. I might think that this obtains even in those places bordering (on Jerusalem). It is, therefore, written here "And they shall place My name," and, elsewhere, (I Kings 11:36) "to place My name there." Just as there, the Temple, so, here, the Temple. In the Temple, with the Tetragrammaton; elsewhere, with an epithet. These are the words of R. Yoshiyah. R. Yonathan says (Shemot 20:21) "Wherever I mention My name, etc.": This is an inverted verse, (to be understood as) "Wherever I am revealed to you, there shall you mention My name." Where am I (i.e., My shechinah) revealed to you? In the Temple. You, too, may mention My name only in the Temple — whence they ruled: It is forbidden to utter the explicit Name (the Tetragrammaton) in the borders (of Jerusalem). "Thus shall you bless the children of Israel": This tells me only of a blessing for (the men of) Israel. Whence do I derive (the same for) women, proselytes, and bondsmen? From "Say to them" — to all of them. Whence do I derive a blessing for the Cohanim (by the L-rd)? From (6:27) "and I shall bless them (the Cohanim)." "Thus shall you bless the children of Israel": face to face. You say face to face, but perhaps face to back is intended! It is, therefore, written "Say to them" (as a man speaks to his neighbor) face to face. "Thus shall you bless the children of Israel": in a loud voice so that the entire congregation can hear." — But perhaps in a whisper is intended. — It is, therefore, written "Say to them" — so that the entire congregation can hear. And whence is it derived that the prayer leader must tell them (the Cohanim) to say? From "Say to them."