Abu Sa'id al-Khudri (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) sent a party to Banu Lihyan and said: "Let one man out of every two go forth." Then he said to "al-qa'idin" (those staying behind): "Whoever among you takes the place of the one going out for jihad in looking after his household and property well, he is given a reward equal to half the reward of the one who goes out for jihad."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17940