Charles Ellicott Commentary 1 Samuel 19:2

"And Jonathan told David, saying, Saul my father seeketh to slay thee: now therefore, I pray thee, take heed to thyself in the morning, and abide in a secret place, and hide thyself:" — 1 Samuel 19:2 (ASV)

Jonathan told David. —The danger Jonathan saw was a very present one. A very slight expression on the part of a powerful king of his earnest desire to get rid of an obnoxious subject, however eminent or great, is sufficient to stir up unscrupulous men to commit the murder, which they might imagine would be acceptable to their master.