Sunan an-Nasa'i, Hadith 3990 ⓘ
It was narrated from 'Abdullah bin Buraidah that his father said: "The Messenger of Allah [SAW] said: 'Killing a believer is more grievous before Allah than the extinction of the whole world.'"
أَخْبَرَنَا الْحَسَنُ بْنُ إِسْحَاقَ الْمَرْوَزِيُّ، - ثِقَةٌ - حَدَّثَنِي خَالِدُ بْنُ خِدَاشٍ، قَالَ حَدَّثَنَا حَاتِمُ بْنُ إِسْمَاعِيلَ، عَنْ بَشِيرِ بْنِ الْمُهَاجِرِ، عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " قَتْلُ الْمُؤْمِنِ أَعْظَمُ عِنْدَ اللَّهِ مِنْ زَوَالِ الدُّنْيَا " .
also referenced under: Book 37, Hadith 25 (In-Book) & Volume 5, Book 37, Hadith 3995 (DarusSalam)