1 Samuel 20:30-33

30Then Saul’s anger burned against Jonathan, and he said to him, “You son of a perverse and rebellious woman! Do I not know that you have chosen the son of Jesse to your own shame and to the shame of the mother who bore you? 31For as long as the son of Jesse lives on this earth, neither you nor your kingdom shall be established. Now send for him and bring him to me, for he must surely die!”

32“Why must he be put to death?” Jonathan replied. “What has he done?”

33Then Saul hurled his spear at Jonathan to kill him. So Jonathan knew that his father was determined to kill David.