Musar for Shabbat 296:7
תנן אם אינו מאמינו מניח טליתו אצלו אי אמרת בשלמא לא ניתנה ליתבע משום הכי מניח טליתו אצלו ועושה עמו חשבון לאחר שבת אלא אי אמרת ניתנה ליתבע אמאי מניח טליתו אצלו ליתן ליה ולתבעיה אמר לא בעינא דליקום בדינא ודיינא
said: It can be claimed. 'R. Joseph said: It cannot be claimed', for if you say that it can be claimed, he [the lender] will come to record it. 'Rabbah said: It can be claimed', for if you say that it cannot, he will not lend him, and so he will come to abstain from the joy of the Festival. We learnt: IF HE DOES NOT TRUST HIM, HE LEAVES HIS CLOAK WITH HIM: now, it is well if you say that it cannot be claimed, therefore he must leave his cloak with him and make a reckoning with him after the Sabbath. But if you say that it can be claimed, why must he leave his cloak with him: let him, lend it and then [re-]claim it? — He says, I do not wish to stand at court and before judges.