משנה על ויקרא 19:36

One who repays his debts after the seventh year, the sages are pleased with him. One who borrows from a convert whose sons had converted with him, the debt need not be repaid to his sons, but if he returns it the sages are pleased with him. All movable property can be acquired [only] by the act of drawing, but whoever fulfills his word, the sages are well pleased with him.