عن عبدالله بن بريدة عن أبيه قال كان رسول الله ﷺ إذا بعث جيشاً أو سريّة أوصى صاحبهم في خاصّة نفسه بتقوى الله وأوصاه بمن معه من المسلمين خيراً ثم قال اغزوا بسم الله وفي سبيل الله قاتلوا من كفر بالله ولا تغُلّوا ولا تغدِروا ولا تُمّثلوا ولا تقتلوا وليداً وإذا لقيتم عدوكم من المشركين فادعوهم إلى الاسلام فإن أسلموا فاقبلوا منهم وكُفّوا عنهم
كتاب السير الصغير للشيباني ١
Abdullah ibn Buraida related from his father, who said: The Messenger of Allah (SAW), whenever he sent forth an army or a brigade, He would order the person in charge of them, in his personal character, to fear Allah, and He would order him to do good towards the Muslims who were with him, then He would say: Attack in the name of Allah and in the cause of Allah, fight those who have disbelieved in Allah, do not steal from the spoils, do not betray, do not mutilate, and do not kill children; and whenever you face your enemy the Idolaters, call them to Islam, and if they yield into Islam, accept it from them and cease from them.
Al-Shaybani, Kitab Al-siyar Al-saghir, item 1