From his father and he was a Companion who said: "When the Messenger of Allah ﷺ dispatched any army or battalion, he would say to them: 'If you see a Masjid, or hear someone calling the Adhan, then do not kill anyone.'"  

كَانَ رَسُولُ اللَّهِ ﷺ إِذَا بَعَثَ جَيْشًا أَوْ سَرِيَّةً يَقُولُ لَهُمْ إِذَا رَأَيْتُمْ مَسْجِدًا أَوْ سَمِعْتُمْ مُؤَذِّنًا فَلاَ تَقْتُلُوا أَحَدًا