Believer's anger leads to separation
Nahj al-Balāgha|Volume 1|Book 3|Chapter 480
٤٨٠. وَقَالَ (عليه السلام): إِذَا احْتَشَمَ الْمُؤْمِنُ أَخَاهُ فَقَدْ فَارَقَهُ.
480. Amīr al-mu’minīn, peace be upon him, said: If a believer enrages (iḥtashama) his brother, it means that he leaves him.