It was narrated from 'Amr bin Shu'aib, from his father, from his grandfather, that the Messenger of Allah ﷺ said:
“A Muslim should not be killed in retaliation for the murder of a disbeliever.”

حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا حَاتِمُ بْنُ إِسْمَاعِيلَ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ عَيَّاشٍ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ " لاَ يُقْتَلُ مُسْلِمٌ بِكَافِرٍ " .