Babylonian Talmud, Taanit 21b-22a

One day Abayi sent two of his disciples to Abba to examine into his actions. Abba entertained them with meat and drink, and even made for them couches of fine wool to use as beds. On the morrow the disciples folded up their woollen couches and carried them into the market in order to sell them. They there encountered Abba. Said they to him: "Let Master estimate the worth of these." And he said: "So much." And they rejoined: "Perhaps they are worth more." And he answered: "For so much money I can purchase them," Said they to him: "These couches are yours; we took them from you." And they continued: "For what reason did you suspect that we took them?" And he replied: "I thought that perhaps some prisoners had to be ransomed, and you did not wish to tell me what amount that would require last night. So you took the couches, and probably thought to tell me this day." They then said: "Then take them back; they are yours." But he answered: "No; I have already made up my mind to devote them to charitable purposes, and therefore I cannot take them back." [Soncino translation. Edited for clarity]