The deep advice of ‘Umar ibn al-Khattab (as narrated by Sa’id ibn al-Musayyib):

“There’s nothing more sufficient than when someone disobeys Allah in dealing with you, you do nothing but obey Allah in dealing with him. Place the affairs of your brother when they reach you upon the best of interpretations until there comes to you clarity which overcomes that. Do not think ill of a statement which comes from another Muslim if you can find a good interpretation for it. Whoever exposes himself to suspicion let him not blame those who then think badly of him, and whoever conceals his secrets, strength of choice will be in his hands.

Hold fast to truthful companions, live with them closely for they are a charm at times of ease and an aid at times of difficulty. Stick to the truth even if the truth kills you, and do not involve yourself with issues that don’t concern you. Do not ask about things which haven’t taken place for indeed, that which has already taken place is enough to preoccupy you from it! Do not seek help or take your affairs to someone who doesn’t wish to see you succeed, and do not befriend the sinful lest you learn from his sins and evil. Keep away from your enemy and be cautious of even your friend, except for the truthful and trusted friend. And no-one is trustworthy except him who fears Allah.

Humble yourself at the graves, lower yourself in obedience and stand firm against disobedience. And when it comes to your affairs, seek counsel only from those who truly fear Allah for indeed, Allah says,

إِنَّمَا يَخْشَى اللَّهَ مِنْ عِبَادِهِ الْعُلَمَاءُ
“…Indeed, it is only those who have knowledge among His Slaves, that truly fear Allah.” [al-Fatir:28]

– The advice of ‘Umar ibn al-Khattab as narrated by Sa’id ibn al-Musayyib
Rawdhat al-‘Uqala’ (pg. 77-78]