How does Issur Frumkin change over the course of the novel, The Way Back?

Issur is the son of Moshe Dovid Frumkin, the town's butcher and one of the wealthiest families. He is pushy, arrogant, and selfish early in the novel, but he seems to change some once he meets Yehuda Leib in the forest. There is no indication why Issur is in the forest at that time of night, other than his decision to go to Zubinsk. HIs role in Avimelekh's death haunts him. As the novel comes to an end, Issur proves his devout nature when he goes in search of someone to lead him in his religious study. He is shocked when that person turns out to be a girl but seems intent on following her.