Birkat Kohanim must be recited aloud and in Hebrew. The kohanim must stand and lift their hands toward the congregation. A kohen who cannot meet these conditions may not perform Birkat Kohanim (SA 128:14; Peninei Halakha: Prayer 20:4).
Before the kohanim lift their hands, they must wash them. There is an allusion to this in the verse: “Lift up your hands in holiness and bless God” (Tehilim 134:2). Any kohen who did not wash his hands may not bless the congregation (Sota 39a).
- Yoĥanan b. Zakai enacted that kohanim not perform Birkat Kohanim while wearing sandals or shoes (as explained in Peninei Halakha: Prayer 20:8).
This is the protocol of Birkat Kohanim: The ĥazan or the gabbai declares “kohanim,” but if only one kohen goes up before the ark, “kohanim” is not declared. This is derived from the verse “Say to them” (Bamidbar 6:23), which is in the plural and indicates that the word “kohanim” is only declared when there are at least two kohanim present (SA 128:10). Birkat Kohanim is not recited by the kohanim on their own. Rather, the ĥazan recites each word and the kohanim repeat after him. At the completion of each verse, the congregation answers “amen.”