The Priestly Blessing (known as 'Birkat Kohanim', exactly 'Blessing of the Cohens') is a Jewish worship which was first-year recited by Aaron, the High Priest in the Holy Temple and brother of Moses. It was instigated at the behest of G-d to bring up His family on His position.
"And the L-rd spoke to Moses, saying; articulate to Aaron and to his sons, saying; so shall you bring up the offspring of Israel....they shall deposit my entitle upon the Children of Israel, and I shall invoke them." (Bamidbar/Numbers 6:23-7).