Sunan an Nasai 4061
The Book of Fighting [The Prohibition of Bloodshed]
أَخْبَرَنَا مَحْمُودُ بْنُ غَيْلاَنَ، قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ بَكْرٍ، قَالَ أَنْبَأَنَا ابْنُ جُرَيْجٍ، قَالَ أَنْبَأَنَا إِسْمَاعِيلُ، عَنْ مَعْمَرٍ، عَنْ أَيُّوبَ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ بَدَّلَ دِينَهُ فَاقْتُلُوهُ " .
It was narrated that Ibn 'Abbas said:"The Messenger of Allah [SAW] said: 'Whoever changes his religion, kill him
Grading: Abu Ghuddah: Sahih · Al-Albani: Sahih · Zubair Ali Zai: Isnaad Sahih
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.