عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((لَا يَحِلُّ دَمُ امْرِئٍ مُسْلِمٍ إِلَّا رَجُلٌ قَتَلَ فَقُتِلَ، أَوْ رَجُلٌ زَنَى بَعْدَ مَا أُحْصِنَ، أَوْ رَجُلٌ ارْتَدَّ بَعْدَ إِسْلَامِهِ))
Narrated from Sayyidah Aisha (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) said: It is not permissible to shed the blood of a Muslim man except in one of three cases: a man who kills a Muslim, so he is killed in retaliation; or a man who commits adultery while being married; or a man who becomes apostate after accepting Islam.