1 Samuel 20:31-33

For as long as the son of Jesse lives on the earth, neither you nor your kingdom will be established. Therefore now, send and bring him to me, for he must surely die.” But Jonathan answered Saul his father and said to him, “Why should he be put to death? What has he done?” Then Saul hurled his spear at him to strike him down; so Jonathan knew that his father had decided to put David to death.