וְעַתָּ֗ה הוֹאֵל֙ וּבָרֵךְ֙ אֶת־בֵּ֣ית עַבְדְּךָ֔ לִהְי֥וֹת לְעוֹלָ֖ם לְפָנֶ֑יךָ כִּֽי־אַתָּ֞ה אֲדֹנָ֤י יְהוִה֙ דִּבַּ֔רְתָּ וּמִבִּרְכָ֣תְךָ֔ יְבֹרַ֥ךְ בֵּֽית־עַבְדְּךָ֖ לְעוֹלָֽם׃ (פ)
Maka sekarang, kiranya Engkau berkenan memberkati keluarga hamba-Mu, supaya tetap ada untuk selama-lamanya di hadapan-Mu, sebab Engkau, ya Tuhan Yang Mahakekal, telah berfirman; dan dengan berkat-Mu kiranya keluarga hamba-Mu diberkati untuk selama-lamanya.”
Ein Yaakov
How does one invite [others to recite a blessing]? With three [people], one says "let us bless [God]". With three and himself, he says "bless [God]". Gemara: Shmuel said, "A person should never exclude himself from the community
Ein Yaakov
Translation: What is the law regarding the blessings of a non-Jew, whether he is a Torah scholar or not? Rabbi says: "If he blesses with enthusiasm, he is a Torah scholar, and if not, he is an ignoramus." Abaye said to Rav Dimi: "But isn't it written (in 2 Samuel 7:29), 'And may Your house be blessed forever from Your blessing'? This is a question." Likewise, in another verse (in Psalm 81:11), it is written, "Open your mouth wide, and I will fill it." This one is written in matters of Torah.
Midrash Tanchuma Buber
[(Numb. 6:23:) THUS SHALL YOU BLESS.] This text is related (to Deut. 26:15): LOOK DOWN FROM YOUR HOLY DWELLING, FROM THE HEAVENS, AND BLESS YOUR PEOPLE. And in the same vein David says (in II Sam. 7:29): SO NOW MAY YOU BE PLEASED TO BLESS YOUR SERVANT'S HOUSE, THAT IT ABIDE BEFORE YOU FOREVER…. AND MAY YOUR SERVANT's HOUSE BE BLESSED FOR EVER WITH YOUR BLESSING{S}. The congregation of Israel said to the Holy One: Sovereign of the World, you tell your priests to bless us.58Tanh., Numb. 2:8, cont.; Numb. R. 11:2. We only need you to bless us. (Deut. 26:15): LOOK DOWN FROM YOUR HOLY DWELLING, FROM THE HEAVENS, <AND BLESS YOUR PEOPLE>. The Holy One said to them: Although I have told the priests to bless you, I am standing along with them and blessing you. For that reason the priests spread their hands.59See Sot. 7:6 for details about how the priests were to hold their hands. <They do so> to say: The Holy One is standing behind us. So also it says (with reference to the Holy One in Cant. 2:9) THERE HE STANDS BEHIND OUR WALL, GAZING THROUGH THE WINDOWS, PEERING THROUGH THE LATTICE, <i.e.> GAZING THROUGH THE WINDOWS, from between the fingers of the priests; PEERING THROUGH THE LATTICE, when they extend their hands. It is therefore stated (in Numb. 6:23:) THUS SHALL YOU BLESS.