1 Samuel 20:30-33

30Then Saul’s rage blazed against Jonathan and he said to him, “You son of a perverse, rebellious woman! Don’t I know that you have chosen the son of Jesse—to your own shame, and to the shame of your mother’s nakedness?

31For as long as the son of Jesse lives on earth, neither you nor your kingship will be secure. Now, send word and bring him to me, for he is a son of death!”

32But Jonathan answered his father Saul, “Why should he be put to death? What has he done?”

33Then Saul hurled his spear at him to strike him down. So Jonathan knew that his father was determined to put David to death.