وَعَنْ سَمُرَةَ رضى الله عنه
قَالَ: قَالَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ -«اُقْتُلُوا شُيُوخَ اَلْمُشْرِكِينَ، وَاسْتَبْقُوا شَرْخَهُمْ»
“Kill the mature men of the polytheists but spare their children.” Related by Abu Dawud and At-Tirmidhi graded it as Sahih.