Tractate Shekalim - Chapter 3 - Mishnah 3 שקלים פרק ג׳ משנה ג׳

[The members] of Rabban Gamaliel’s household used to enter [the chamber] with their shekel between their fingers, and throw it in front of him who made the appropriation, while he who made the appropriation purposely pressed it into the basket. He who made the appropriation did not make it until he first said to them: “Should I make the appropriation?” And they say to him three times: “Make the appropriation! Make the appropriation! Make the appropriation!”