The Prophet ﷺ said: Faith prevented assassination. A believer should not assassinate.  

عَنِ النَّبِيِّ ﷺ قَالَ الإِيمَانُ قَيَّدَ الْفَتْكَ لاَ يَفْتِكُ مُؤْمِنٌ  

[Machine] The Messenger of Allah ﷺ said: "The believer is affable, and there is no good in one who is not affable or is not befriended."  

قَالَ رَسُولُ اللهِ ﷺ الْمُؤْمِنُ مَأْلَفَةٌ وَلَا خَيْرَ فِيمَنْ لَا يَأْلَفُ وَلَا يُؤْلَفُ  

A man came to az-Zubair bin al-’Awwam ؓ and said: “Shall I kill ʿAli for you?” He said: “No; how can you kill him when he has the troops with him?” He said: “I will catch up with him and assassinate him.” He said: “No. The Messenger of Allah ﷺ said: Faith prohibits assassination; no believer should resort to that.” Al-Hasan said: A man came to az-Zubair bin al-ʿAwwam ؓ and said: “Shall I not kill ʿAli for you?” He said: “How can you kill him when he has people with him?” (and he narrated a similar report.)  

لَا إِنَّ رَسُولَ اللهِ ﷺ قَالَ إِنَّ الْإِيمَانَ قَيَّدَ الْفَتْكَ لَا يَفْتِكُ مُؤْمِنٌ  

[Machine] The Messenger of Allah ﷺ said, "A believer is friendly and there is no good in one who is not friendly and does not seek friendship."  

قَالَ رَسُولُ اللهِ ﷺ «الْمُؤْمِنُ مَأْلَفَةٌ وَلَا خَيْرَ فِيمَنْ لَا يَأْلَفُ وَلَا يُؤْلَفُ»  

"الإِيمان قيدُ الْفَتْكِ، لَا يفتَكُ مُؤمنٌ" .