Compiled by Imam Yahya ibn Sharaf al-Nawawi
وعن أبي سعيد الخدري رضي الله عنه أن رسول الله صلى الله عليه وسلم بعث إلى بني لحيان، فقال: "لا ينبعث من كل رجلين أحدهما، والأجر بينهما" ((رواه مسلم)).
The Messenger of Allah (ﷺ) sent an expedition to Banu Lahyan and said, "One man from every two should join the fighting force, and the reward will be shared amongst them equally."[Muslim].Another narration in Muslim is: The Messenger of Allah (ﷺ) said, "Let one of every two men go forth", and added: "Whoever stays behind (and looks well after the family and the property of those who have joined the expedition) will get half the reward of the warrior."