Jihad (Kitab Al-Jihad)
Dawud :: Book 14 : Hadith 2528
Narrated Jabir ibn Abdullah:
Once the Apostle of Allah (peace_be_upon_him) intended to go on an expedition. He said: O group of the emigrants (Muhajirun) and the helpers (Ansar), among your brethren there are people who have neither property nor family. So one of you should take with him two or three persons; with me. I also rode on my camel by turns like one of them.