1 Samuel 20:31-33

Amplified Bible

³¹ For 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 ^[a]must die.” ³² Jonathan answered Saul his father, “Why must he be put to death? What has he done?” ³³ Then 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.