Al-Tirmidhi HadithHadith 184 Narrated byMu'adh ibn Jabal

Allah's Messenger (peace be upon him) said: Verily Satan is the wolf of a man just as the wolf is (the enemy) of a flock. He seizes the solitary sheep going astray from the flock or going aside from the flock. So avoid the branching paths; it is essential for you to remain along with the community.