Bava Mezia 43a. The Mishna says that the fact that one gives over some money to guard to a money changer that is not wrapped up, that means the money changer is already responsible. To Rav Huna he is a borrower. To Rav Nahman he is a paid guard.

Later Rav Nahman asks on Rav Huna from a braita that says if gizbar [one appointed over Temple funds] gives over money to a money changer, the money changer trespasses the prohibition of {Meila} using unauthorized temple funds] if he uses the money.

The question I have at this point even before getting into the Tosphot on the page is how this relates to what Tosphot says later on on page 99a. There Rav Ami said if one gives over some object [bedek habait] to another person--as soon as he gives it over, he trespasses the prohibition. even before the other person uses it.

This relates to an essay in Rav Shach's Avi Ezri conserning Meila.