1,226. Using a Deposited Item

188:2 If a person deposits an object with his fellow, the one holding it is not permitted to use the object for his own needs, even if the item will not be ruined by this use. Doing so would be like borrowing something without the owner's knowledge, and one who borrows without the owner's knowledge is considered a thief. If the one holding the item knows for sure that the depositor is not bothered by such use, then it would be permitted. Some authorities still prohibit doing so because it is a deposit. It is even prohibited with an item that is not common to deposit, because it is prohibited for one to make personal use of a deposit. One should act stringently even in these circumstances.

188:3 A person is obligated to watch the deposited item in the best way possible for such objects. Even if he is not so careful with his own possessions, he is obligated to be more careful with a deposit.