Sahih al-Bukhari, Volume 5, Book 59, Hadith 400 (USC-MSA)

Narrated Abu Huraira: Allah's Messenger (pointing to his broken canine tooth) said, "Allah's Wrath has become severe on the people who harmed His Prophet. Allah's Wrath has become severe on the man who is killed by the Apostle of Allah in Allah's Cause."

حَدَّثَنَا إِسْحَاقُ بْنُ نَصْرٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنْ مَعْمَرٍ، عَنْ هَمَّامٍ، سَمِعَ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ اشْتَدَّ غَضَبُ اللَّهِ عَلَى قَوْمٍ فَعَلُوا بِنَبِيِّهِ ـ يُشِيرُ إِلَى رَبَاعِيَتِهِ ـ اشْتَدَّ غَضَبُ اللَّهِ عَلَى رَجُلٍ يَقْتُلُهُ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي سَبِيلِ اللَّهِ ‏" ‏‏.‏

sunnah.com