Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 72

وَعَنْ أَبِي هُرَيْرَةَ قَالَ: قِيلَ: يَا رَسُولَ اللَّهِ ادْعُ عَلَى الْمُشْرِكِينَ. قَالَ: «إِنِّي لَمْ أُبْعَثْ لَعَّانًا وَإِنَّمَا بُعِثْتُ رَحْمَةً» . رَوَاهُ مُسْلِمٌ

Abu Huraira told that when God’s messenger was asked to invoke a curse on the polytheists, he replied, “I was not sent as one given to cursing; I was sent only as a mercy.” Muslim transmitted it.