Abandoning a fellow Muslim
Narrated Abu Aiyub Al-Ansari: Allah’s Messenger (ﷺ) said, “”It is not lawful for a man to abandon his brother Muslim for more than three nights.””
Hitting a Muslim on the face is forbidden
Narrated Abu Huraira: The Prophet (ﷺ) said, If somebody fights (or beats somebody) then he should avoid the face.