Hanash (al-San'ani) (may Allah have mercy on him) said: I was present with Sayyiduna Ruwayfi' bin Thabit (may Allah be pleased with him) when he conquered Jarbah. When he had conquered it, he stood among us to deliver a sermon and said: I will tell you only what the Messenger of Allah (peace and blessings be upon him) said to us on the day of Hunayn. He (peace and blessings be upon him) said: "It is not lawful for a man who believes in Allah and the Last Day to sell any of the spoils of war before they are distributed; it is not lawful for a man who believes in Allah and the Last Day to use a mount from the fay' of the Muslims in such a way that, when he has made it emaciated, he returns it; nor may he wear a garment in such a way that, when he has worn it out, he returns it (to the fay')."
Hadith Referenceالمعجم الكبير للطبراني / باب الراء / 4470