Abu Hurayrah (RA) reported that Allah’s Messenger said, “There is no one who dies but reproaches himself.” The sahabah asked, “And, what is his regret, O Messenger of Allah?” He said, “If he was righteous he will regret why he did not increase (his righteousness) and if he was evil then he will regret why he did not pull himself out (of it).”
[Nisai 1814]