The ruler not ruling in an honest manner
I heard the Prophet (ﷺ) saying, “Any man whom Allah has given the authority of ruling some people and he does not look after them in an honest manner, will never feel even the smell of Paradise.”
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.