Al-Adab Al-Mufrad, Book 15, Hadith 321 (English) ⓘ

Abu Hurayra said, "The Messenger of Allah, may Allah bless him and grant him peace, was asked, "Messenger of Allah, invoke a curse for us against the idolaters.' He replied, 'I was not sent as a curser. I was sent as a mercy.'"

حَدَّثَنَا مُحَمَّدٍ قَالَ‏:‏ عَبْدُ اللهِ بْنُ محمد قال حَدَّثَنَا مَرْوَانُ بْنُ مُعَاوِيَةَ، حَدَّثَنَا يَزِيدُ، عَنْ أَبِي حَازِمٍ، عَنْ أَبِي هُرَيْرَةَ قَالَ‏:‏ قِيلَ‏:‏ يَا رَسُولَ اللهِ، ادْعُ اللَّهَ عَلَى الْمُشْرِكِينَ، قَالَ‏:‏ إِنِّي لَمْ أُبْعَثْ لَعَّانًا، وَلَكِنْ بُعِثْتُ رَحْمَةً‏.‏