King Saul was still trying to kill David.  David had to flee, and went to the priests at Nob.  The priests fed David and his companions.   Doeg, King Saul's head shepherd, found out about it and told Saul.  King Saul was so angry that he told his soldiers to kill the priests at Nob.  The soldiers were not willing to kill the Lord's priests, so Saul had Doeg do it.  Doeg killed 85 priests that day.