Then said David to Jonathan, Who shall tell me if perchance your father answer you roughly?
There are several oaths and strong affirmations in this chapter (1 Samuel 20:3; 1 Samuel 20:12-13; 1 Samuel 20:16-17; 1 Samuel 20:23; 1 Samuel 20:42). The one that David made in 1 Samuel 20:3 is very strong. He believed correctly that he was in mortal danger, and he tried to make Jonathan see this. Jonathan was open to anything David wanted to suggest to prove his point (1 Samuel 20:4).