Mukhtasar Muslim

It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) sent a messenger to Banu Lihyan and said: "From every household, one of every two men should go forth." Then he said to those who remained at home: "Whoever looks after the family and wealth of the one who goes out, he will receive half the reward of the Mujahid."