I heard the following story from the baalei hamaaseh:
Someone divorced his wife just a month after their wedding. He remarried, there was peace in his second home. (Although, he had to wait a long time until he had a child, one son, many years after the chasunah.) For years, he held a grudge against his first wife and her family, due to the tzaros he suffered from them.
His former in-law's family suffered immensely. He had four children in shidduchim, and for ten years since the divorce, no one was got engaged. In addition, he became ill with Covid in פ"תש. Many people came to the former husband, asked him to forgive his former wife and family, but he refused.
His former father-in-law became even more ill, and he needed a respirator. Again, someone came to the former son-in-law, and asked him to forgive.
This former son-in-law went to the kever of his rebbe of Bobov zy'a in New Jersey, and davened for his former father-in-law. At the kever, he expressed his dilemma. We wanted to forgive them because he didn't want to be responsible for the death of his fellow man, but he said that it was still very hard for him to bring himself to forgive.
From there, he went to the kever of Reb Shmuel Tzvi of Spinka, zy'a, which is near the Bobover Rav's tzion, and he davened there as well, and once again, expressed the struggle he is going through, to forgive.
As he was returning home, he received a phone call from the Rav of Kroli (who is a son of Reb Shmuel Tzvi of Spinka). (This yungerman is a talmid of the Rav of Kroli.) As they spoke, the yungerman said, "Regards from your father."
The Rav of Kroli asked him what he meant, and he explained that he davened there for his former father-in-law, and he told the Kroli Rav about his struggle to forgive.
The rav of Kroli said, "To forgive them is to go beyond your nature. But if you will do so, Hashem will treat you beyond nature, and you will receive a double yeshuah."
The rav of Kroli told him stories of tzaddikim who were mochel those who harmed them, and he repeated several times, "Forgive your former wife and her parents, and you will receive a double yeshuah."
The yungerman said that he forgives. The Kroli Rav told him that it isn't enough. He must say it in front of three people that he forgives, and he did so.
This occurred on Thursday. On Friday, the hospital took the former father-in-law off the respirator. Shabbos, he stood on his own, and motzei Shabbos, he returned home. The hospital stated that there was no reason to hold him anymore, as he had healed so well.
Two weeks later, one of the sons of his former father-in-law was engaged. Exactly a year later (on the same date that the son became a chasan, only a year afterwards), the yungerman had his own yeshuah, a double yeshuah, because his wife gave birth to twins. It was as the Kroli Rav told him, if he forgives, he will experience a double salvation.
