1 Samuel 20:8, 13-17, 30-34, 42

Therefore thou shalt deal kindly with thy servant; for thou hast brought thy servant into a covenant of the LORD with thee: notwithstanding, if there be in me iniquity, slay me thyself; for why shouldest thou bring me to thy father?

the LORD do so and much more to Jonathan: but if it please my father to do thee evil, then I will shew it thee, and send thee away, that thou mayest go in peace: and the LORD be with thee, as he hath been with my father. And thou shalt not only while yet I live shew me the kindness of the LORD, that I die not: but also thou shalt not cut off thy kindness from my house for ever: no, not when the LORD hath cut off the enemies of David every one from the face of the earth. So Jonathan made a covenant with the house of David, saying, Let the LORD even require it at the hand of David's enemies. And Jonathan caused David to swear again, because he loved him: for he loved him as he loved his own soul.

Then Saul's anger was kindled against Jonathan, and he said unto him, Thou son of the perverse rebellious woman, do not I know that thou hast chosen the son of Jesse to thine own confusion, and unto the confusion of thy mother's nakedness? For as long as the son of Jesse liveth upon the ground, thou shalt not be established, nor thy kingdom. Wherefore now send and fetch him unto me, for he shall surely die. And Jonathan answered Saul his father, and said unto him, Wherefore shall he be slain? what hath he done? And Saul cast a javelin at him to smite him: whereby Jonathan knew that it was determined of his father to slay David. So Jonathan arose from the table in fierce anger, and did eat no meat the second day of the month: for he was grieved for David, because his father had done him shame.

And Jonathan said to David, Go in peace, forasmuch as we have sworn both of us in the name of the LORD, saying, The LORD be between me and thee, and between my seed and thy seed for ever. And he arose and departed: and Jonathan went into the city.