Hadith 1438
ان الشيطان ذئب الانسان كذئب الغنم يأخذ الشاة القاصية . . .
"Satan is a wolf to humans just as a wolf is to goats; he seizes the goat that separates from the herd. So beware of separating yourselves, and adhere to the congregation, public places, and the mosque."