The great gadol and tzadik, Rav Chaim Kreiswirth, the Chief Rabbi of Belgium, related that an act of chesed saved his life.
One time the Jews were rounded up by the gestapo and each person was asked if he was a Jew. One person denied it [Rav Chaim said that he doesn't know if this person survived the war]. Rav Chaim affirmed that he was. So the Nazis told him to pray his last prayer because he is about to be killed.
Rav Chaim asked Hashem to save him in the merit of his helping Yeshaya'le Mishna. A Nazi was told to take him to the forest and kill him there. On the way there, Rav Chaim asked the Nazi if it was right to kill young people. The Nazi said that it wasn't. He added that he himself has 3 children. He shot in the air and told Rav Chaim to run away.
Who was Rav Yeshayale Mishna? When Rav Chaim was 17 years old, he was giving shiurim in Warsaw and had a room with one bed. One time, the Grodzisker Rebbe sent to him a blind man named Reb Yeshay'le Mishna and asked to set him up with a place to stay so that he can undergo treatments for his eyes. Rav Chaim couldn't find him a place to stay so he gave up his own bed and slept on the cold floor for a few weeks until Reb Yeshaya received his treatment and was healed.
Rav Chaim said that it was very difficult but he believes that in the zchus of this mitzva he was saved.