Messenger of Allah ﷺ sent us in a mission (i.e., an army-unit) and said, "If you find so-and-so and so-and-so, burn both of them with fire." When we intended to depart, Messenger of Allah ﷺ said, "I have ordered you to burn so-and-so and so-and-so, and it is none but Allah Who punishes with fire, so, if you find them, kill them (i.e., don't burn them)."
أَنَّهُ قَالَ بَعَثَنَا رَسُولُ اللَّهِ ﷺ فِي بَعْثٍ فَقَالَ إِنْ وَجَدْتُمْ فُلاَنًا وَفُلاَنًا فَأَحْرِقُوهُمَا بِالنَّارِ ثُمَّ قَالَ رَسُولُ اللَّهِ ﷺ حِينَ أَرَدْنَا الْخُرُوجَ إِنِّي أَمَرْتُكُمْ أَنْ تُحْرِقُوا فُلاَنًا وَفُلاَنًا وَإِنَّ النَّارَ لاَ يُعَذِّبُ بِهَا إِلاَّ اللَّهُ فَإِنْ وَجَدْتُمُوهُمَا فَاقْتُلُوهُمَا