Jami` at-Tirmidhi 1408
جامع الترمذي#1408SahihNarrated Buraidah:from his father who said: "Whenever the Messenger of Allah (ﷺ) dispatched a commander of an army he would exhort him personally; that he should have Taqwa of Allah, and regarding those of the Muslims who are with him; that he should be good to them. He would say: 'Fight in the Name of Allah and in Allah's curse. Fight those who disbelieve in Allah and fight, do not be treacherous, nor mutilate, nor kill a child
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Bashar Awad MaaroufHasan Sahih
Zubair Ali ZaiSahih Muslim
In-book reference: 16:24