Who is Dr. Abulafia from The Source; a Novel and what is their importance?

Abulafia is a Spanish physician who watches one of his patients burned by the Inquisition. He has Jewish ancestors and is worried that his patient might have informed on him. He flees Spain and goes to Tunis, leaving his wife and family behind. He eventually settles in Safed. He marries Sarah, the daughter of Zaki. He still feels guilty for leaving his wife and sons behind in Spain. They were burned by the Inquisition.