سأل رجل عبد الله بن عمر عن عثمان فقال أذنب يوم أحد ذنبا عظيما فعفا الله عنه و أذنب فيكم ذنبا صغيرا فقتلتموه
Abdullah bin Umar may Allah be pleased with him said about Uthman may Allah be pleased with him: He committed a major sin on the day of Uhud by leaving the battlefield but Allah forgave him ( Quran 3:155) and he committed a minor sin in terms of your rights and you killed him.
A spiritual Ishmaelite 