Musar for Shabbat 166:12

"I reflected upon the words of Chazal (Shabbath 83b): 'Torah endures only with one who "kills himself" over it, etc.'" That is, [one should imagine] that he has already died, and had completed all of his affairs, and, with them, his life. And he were brought to judgment before the King of kings, the Holy One Blessed be He, for all of the things for which he had spent his life in vanity, and emerging "guilty" in the Heavenly din, he screamed: "Woe unto me, for the wickedness of my acts and of my affairs!" If in the midst of all this he were permitted to return immediately to this world and to repent, he certainly would not hesitate for a moment, and would not incline his ear at all to hear of the business of his house.