(8) باب تَحْرِيمِ قَتْلِ النِّسَاءِ وَالصِّبْيَانِ فِي الْحَرْبِ
It is narrated by Ibn 'Umar that a woman was found killed in one of these battles; so the Messenger of Allah (ﷺ) forbade the killing of women and children.
Reference: Sahih Muslim 1744 b
In-book reference: Book 32, Hadith 29
USC-MSA web (English) reference(deprecated numbering scheme): Book 19, Hadith 4320