مسند امام احمد بن حنبل · Hadith 4873

Ibn 'Awn said: I wrote to Naafi and asked him: What kept Ibn 'Umar from going out on campaign? What options should (the Muslim army) offer to the enemy before attacking them? And is it permissible for a man to change (at the enemy) on his own and without the permission of his commadner when he is part of a brigate? He wrote back to him and said- Ibn 'Umar's sons are going out on campaign, and he is giving mounts (for the troops).and he used to say: The best deed after prayer is jihad for the sake of Allah, may He be exalted. Nothing prevented Ibn 'Umar from going out on campaign expect the fact that he was taking care of the matters that ‘Umar had left behind, looking after young children and earning a living by looking alter a lot of livestock. The messenger of Allah (PBUH) raided Banu’l-Mustaltq and caught them unawares when they were givmg water to their cattle. He killed their warriors and took their women and children captive, and Juwayriyah bint al-Haanth fell to his lot. He [Naafi'j said: Ibn ‘Umar told me this hadeeth, and he was a member erf that army they only used to offer options to the enemy in the early days of islam And a fighter should not charge against the enemy without the pemrussiion of his commander.