1 Samuel 20:32-34

32And Jonathan answered Saul his father, and said to him, “Why should he be killed? What has he done?”

33Then Saul cast a spear at him to kill him, by which Jonathan knew that it was determined by his father to kill David.

34So Jonathan arose from the table in fierce anger, and ate no food the second day of the month, for he was grieved for David, because his father had treated him shamefully.