What does 1 Samuel 23:17 mean?

Jonathan told him, Don't be afraid. My father Saul won't find you. You're going to be king over Israel, and I'll be right there beside you. Even my father knows this deep down. 1 Samuel 23:17 - Modern Text Bible

(Jonathan reassures David that Saul won't succeed. He affirms David's future as king and promises his own loyalty, even though his father is the current king.)