Anyone among you stays behind and takes good care of the family and property of a warrior (in the cause of Allah) will receive half the reward of the warrior

The Hadīth of Abu Sa‘īd al-Khudri (may Allah be pleased with him) shows that the Messenger of Allah (may Allah's peace and blessings be upon him) wanted to dispatch an army to Banu Lahyān, who were one of the most famous clans of the tribe of Hudhayl. Scholars agreed that Banu Lahyan were disbelievers at that time, so the Prophet dispatched an army to invade them, saying to that army: Let one of every two men proceed to join the military force, which means half the men of every tribe should go.

He stated that both the worrier and the one who stays behind to take care of the worrier's family and property will share the reward. This is confirmed in a previous Hadīth that reads: "Anyone stays behind a warrior in the cause of Allah has indeed participated in the raid,"

and the other explicit Hadīth narrated by Imām Muslim that reads: "Anyone among you stays behind and takes good care of the family and property of a warrior in the cause of Allah will receive half the reward of the warrior". This means that the Prophet (may Allah's peace and blessings be upon him) ordered that one of every two should join the army and the other should stay behind to look after the warrior's family and receive half the reward of the warrior.

The other half would be for the warrior himself.