1 Samuel 20:10 (KJV)

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?

And Jonathan said, Far be it from thee: for if I knew certainly that evil were determined by my father to come upon thee, then would not I tell it thee?

Then said David to Jonathan, Who shall tell me? or what if thy father answer thee roughly?

And Jonathan said unto David, Come, and let us go out into the field. And they went out both of them into the field.

And Jonathan said unto David, O Lord God of Israel, when I have sounded my father about to morrow any time, or the third day, and, behold, if there be good toward David, and I then send not unto thee, and shew it thee;