LEV614 The twentieth principle (of repentance) is doing whatever one can to return the many from sin, as the pasuk says (Yechezkel 18:30), "Repent and bring [others] back from all your iniquities" -- from here we learn that this is one of the principles of repentance. The pasuk also says [this verse] "Reprove your fellowman, and do not bear a sin because of him" -- from here we see that if he does not reprove the other person, he will be punished for his [own] sins (by not rebuking others, his repentance for his own sins will be lacking, and he will be punished (Kanfei Yonah). And David [HaMelech], a"h, said in the psalm [that is the foundation for the principles] of repentance (Tehillim 51:15): "I will teach the iniquitous Your ways, and sinners will return to You."