The news about what Saul did to the inhabitants of Nob (1 Samuel 22:1–23) would have spread throughout Israel. As a result, most people were eager to tell Saul about David’s whereabouts to make sure that his anger did not come down upon them. Most likely it was people from Ziph that told Saul about David’s journey to Engedi.
1 When Saul returned from following the Philistines, he was told, “Behold, David is in the wilderness of Engedi.”