Shortly after the Slabodka yeshiva had arrived in Minsk, which was near the battlefront, it was forced to flee to a safer city, Kremenchuk. However, Sarna chose not to join the yeshiva, but remained in Smilowitz, studying for a year and a half in an inn with the students of the Raduń Yeshiva. During this period, he developed close relationships with the Chofetz Chaim and Raduń's "rosh yeshiva", Naftoli Trop, and later referenced this brief period as one of the most beautiful in his life.