It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) set out for Hunayn. Then he sent a man to Safwan bin Umayyah and asked him for coats of mail; he had one hundred coats of mail. He said: "O Muhammad! Is it by force?" He (peace and blessings be upon him) said: "No, rather it is a loan; they will be returned. We will give them back to you." Then he (peace and blessings be upon him) went on the expedition.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العارية / 11477