From Sa’b ibn Juthama (may Allah be pleased with them), who said: The Prophet (SAW) passed by me either at Abwaa’ or at Waddan, and He was being asked about the people of the land – could the Idolaters [Mushrikun] be attacked by surprise at night but maybe some of their women and children would be struck? He said: They belong to them.
- Sahih Al-Bukhari, The book of jihad and campaigns

His words “they belong to them” : that is, in this condition regarding the command. The intended meaning is not permission to kill them on purpose; rather the meaning is that, if the fathers can not be reached except by treading on the women and children, and if they are struck due to being intermingled with them, then killing them is permitted.