It is narrated from Sayyiduna Abu Sa'id (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) sent a party towards Banu Lihyan and said: "Of every two men, let one go out for jihad." Then he (peace and blessings be upon him) said to those who stayed behind: "Whoever looks after the household and property of the one who goes out for jihad in a good way will receive a reward equal to half the reward of the one who goes out for jihad."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17896