What does 1 Samuel 20:3 mean?

But David insisted, Your father knows we’re close. He probably told himself, Don’t let Jonathan find out or he’ll take David’s side. But I’m telling you, as sure as we’re alive, I’m one step away from death. 1 Samuel 20:3 - Modern Text Bible

(David explains that Saul is deliberately keeping Jonathan in the dark because he knows Jonathan would protect David. David feels his life is in real danger.)