Мидраш к Рут 4:2

(Fol. 7b) R. Nachman said: "Huna b. Nathan related to me the following Baraitha: Whence do we learn that the nuptial benedictions ought to be pronounced in the presence of ten? It is said (Ruth 4, 2) And he took ten men." R. Abahu said: "From here (Ps. 68, 27) In assemblies bless ye God, praise the Lord, ye sprung from Israel's fountain." But what interpretation does R. Nachman give to the latter passage? He needs it for the [interpretation of the] following Baraitha. R. Maier was accustomed to say: "Whence do we learn that even the embryos in the bowels of their mother proclaimed the song at the Red Sea? It is said: In assemblies bless ye, God [praise] the Lord, ye sprung from Israel's fountain."

“He took ten men of the elders of the city, and said: Sit here, and they sat” (Ruth 4:2).
“He took ten men of the elders of the city.” Rabbi Alexandri said: From here [it may be derived] that lesser people are not permitted to sit unless the greater person grants him permission. Rabbi Pinḥas said: From here [it may be derived] that the court appoints elders to [attend] their wedding feasts.²³⁴The court appoints elders to attend wedding feasts so that the celebration will remain appropriate. Boaz invited the elders to sit because he intended to marry Ruth at that very gathering. Rabbi Elazar ben Rabbi Yosei said: From here [it may be derived] that the blessing of the groom is with ten.²³⁵The seven blessings recited at the wedding ceremony require a quorum of ten men. Rabbi Yudan ben Pazi said: Not only when a bachelor [marries] a virgin, but even when a widower [marries] a widow [these blessings are recited, but] only if there are ten.

"Upon a ten-stringed instrument and upon the psaltery" (Ps. 92:8). All testimonies reliable to Israel are (celebrated) with ten (males). The harp upon which David played had ten strings. The testimony for the dead is through ten (males). The testimony for the (public) benediction of (God's) Name is through ten (males). The testimony of the covenant of circumcision is through ten (males). The testimony for Chalizah is through ten (males), as it is said, "And he took ten men of the elders of the city" (Ruth 4:2).