1 Samuel 20:30-34

30Then Saul’s anger burned against Jonathan and he said to him, “You son of a wayward, rebellious woman! Do I not know that you have chosen the son of Jesse [over me] to your own shame, and to the shame of your mother’s nakedness?

31For as long as the son of Jesse lives on the earth, neither you [as heir to the throne] nor your kingdom will be established. So now, send [someone] and bring him to me, for he must die.”

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

33Then Saul hurled his spear at him to strike him down, so Jonathan knew [without any doubt] that his father had decided to put David to death.

34Then Jonathan stood up from the table in the heat of anger, and ate no food on that second day of the new moon (month), for he grieved and worried about David because his father had dishonored him.