Michael Carasik, author of the Commentator’s Bible series, guest blogs for JPS in a post  discussing the priestly benediction and the commentary surrounding it.

Aaron lifted his hands toward the people and blessed them; and he stepped down after offering the sin offering, the burnt offering, and the offering of well-being. Moses and Aaron then went inside the Tent of Meeting. When they came out, they blessed the people; and the Presence of the Lord appeared to all the people.  -Leviticus 9:22-23

The scene is the inauguration of the Tabernacle—the Tent that housed the Ark during the Israelites’ journeys through the wilderness. It’s also the first day of operation for the newly ordained priests: Aaron and his four sons.
So first Aaron blessed the people; then Aaron and Moses went into the Tent, came back out, and blessed the people again. But how did they do it?
The commentators disagree. Now, you can find out how and why, in the Leviticus volume of my Commentators’ Bible series—just published by JPS. This post will introduce you to three of them: Rashi, Nahmanides, and Abraham ibn Ezra (we’re giving Rashi’s grandson, Rashbam, the day off today).

Rashi says the blessing Aaron recited in v. 22 was this:

Don’t recognize it? It’s the priestly blessing of Numbers 6:22-24, still recited in synagogues today (go to the Israel Museum web site to learn about the amazing photo):

The LORD bless thee, and keep thee:
The LORD make his face to shine upon thee, and be gracious unto thee:
The LORD lift up his countenance upon thee, and give thee peace.
- from the JPS 1917 translation

The LORD bless you and protect you!
The LORD deal kindly and graciously with you!
The LORD bestow His favor upon you and grant you peace!
- from the JPS 1962 ?** translation

But when Moses and Aaron came out of the Tent, they offered a different blessing, according to Rashi. The Bible does not give its text here, but the text is found in the Bible, in Psalm 90, which is identified in v. 1 as “A prayer of Moses.” In v. 17 of his prayer, Moses says, “May the favor of the LORD, our God, be upon us!”

Rashi explains why:

It was to say to say, “May it be God’s will that the Shekhinah rest upon the Tabernacle you have made.” For all during the first seven days of the ordination procedure, when Moses set up the Tabernacle, served there, and then disassembled it each day, the Shekhinah did not rest upon it. The people were depressed, saying, “Our master Moses! All this trouble we took was so that the Shekhinah would settle among us and we would know that we were forgiven for the sin of the Golden Calf.”

Nahmanides always takes Rashi’s explanations seriously:

If this was indeed the priestly blessing of Num. 6:24–26, as Rashi thinks, then Num. 6:23, “Speak to Aaron and his sons: Thus shall you bless the people of Israel,” must also have preceded our passage. And perhaps it did, since the Numbers passage seems to be describing “the day that Moses finished setting up the Tabernacle” (Num. 7:1).

He often disagrees with them, however:

But it might also be possible simply to understand Aaron doing the same here as did Solomon at the inauguration of the Temple, when “he spread the palms of his hands toward heaven … and in a loud voice blessed the whole congregation of Israel” (1 Kings 8:22, 55). That would explain why the text does not record that Moses commanded Aaron to do so.

Ibn Ezra takes a more practical interest in Aaron’s “lifting his hands”:

Based on this verse, our predecessors have passed on the tradition that the priests must lift their hands high when they offer the priestly blessing.

Leave it to Nahmanides, however, to bring a kabbalistic element into the discussion. To find it, however, you’ll have to go to the other volume of The Commentators’ Bible that been published so far—Exodus—and the famous passage where Moses lifts up his hands to give Israel victory:

Exodus 17:8 Amalek came and fought with Israel at Rephidim. 9 Moses said to Joshua, “Pick some men for us, and go out and do battle with Amalek. Tomorrow I will station myself on the top of the hill, with the rod of God in my hand.” 10 Joshua did as Moses told him and fought with Amalek, while Moses, Aaron, and Hur went up to the top of the hill. 11 Then, whenever Moses held up his hand, Israel prevailed; but whenever he let down his hand, Amalek prevailed. 12 But Moses’ hands grew heavy; so they took a stone and put it under him and he sat on it, while Aaron and Hur, one on each side, supported his hands; thus his hands remained steady until the sun set. 13 And Joshua overwhelmed the people of Amalek with the sword.

Says Nahmanides:

His hands remained steady. This translation is correct. But according to the Way of Truth, he held ten fingers high to heaven to allude to the ten sefirot, and to cleave to the aspect of Faith that was fighting for Israel. The subject of the priests’ holding up their hands when they bless the people, and the mystery behind it, is also clarified by this text.

The Torah is not a book to pick up and read from beginning to end, once and be done with it, but a book that Jews return to over and over again to learn new insights. The Commentators’ Bible is intended to bring a deeper level of Torah study within the reach of more English-speaking Jews than ever before.

I am looking forward to learning with you!