Sayyiduna Abu Las al-Khuza'i (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) mounted us for Hajj on weak camels from the camels of charity. We said: O Messenger of Allah! We do not think these can carry us. He (peace and blessings be upon him) said: "There is no camel but that on its hump there is a devil. So when you ride them, remember the blessing of Allah as Allah has commanded you, then put them to use for yourselves, for in reality it is Allah who carries."
Hadith Referenceالمعجم الكبير للطبراني / مسند من يعرف بالكنى / 19040