Musannaf Ibn Abi Shayba 33:251

Abu Usama narrated to us, he said: Wadi'ah al-Ansari narrated to us, he said: Umar said: Do not involve yourself in what does not concern you, and keep away from your enemy, and beware of your friend except the trustworthy among the people. And there is no trustworthy person except one who fears Allah. Do not accompany the wicked, lest you learn from his wickedness, and do not let him know your secret, and consult in your affairs those who fear Allah.