It is narrated from Sayyiduna Samurah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "The hand is responsible for what it has taken until it returns it." Then al-Hasan (the narrator) forgot his hadith and said: "He is your trustee; he is not liable."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العارية / 11482