GEN1091 We should forgive people who have wronged us. Avimelech caused Avraham much grief by trying to take away his wife, Sara.   Nevertheless, when Avimelech apologized, Avraham forgave him and prayed to God on his behalf.  The Mishnah cites Abraham’s behavior as an example of how we are obligated to react when asked for forgiveness.  We are forbidden to be cruel toward someone who sincerely seeks our forgiveness; rather we must forgive him wholeheartedly.   Baba Kama 92a; Hilchot Diaso 6:6; Choshen Mishpat 422:1.   It should be noted that Avimelech did not regret his behavior on his own.   He asked Abraham for forgiveness only after God appeared to him in a dream and threatened his life unless he returned Sara to Abraham.   Nevertheless, Abraham forgave him wholeheartedly and prayer for his welfare. Rabbi Avraham Shmuel Finkel in Yad Eliezer, vol. 1, p. 174.  [See also, detailed discussion of laws of forgiveness].   PLYN 82