Abdullaah ibn al-Mubaarak Reference: Seer A'alaam an Nubalaa': vol 8, p. 406
Imaam Ath Thahabi Rahimahullah mentions in his monumental book "Seer Aŭalaam an Nubalaaŭ Vol.8 P.406 on the authority of Abdullah Ibn Al Mubaarak Rahimahullah (181H.):
ŭThe people of knowledge and insight do not consider themselves safe from four things:
1) A past sin he committed which he does not know what Allaah will do with it (either forgive and pardon him for it or punish him with it);
2) What is left of his life, whether there is something therein waiting to destroy him;
3) A favor that Allaah bestowed upon him, perhaps it is a plot which will lead him step by step to his eventual destruction and ruin;
4) Deviance which is beautified for him so that he sees it to be guidance and in a split second, his heart can deviate and he will be stripped of his deen and he doesn't even realize it.ŭ