In 1 Samuel 20, David and Jonathan arrange an elaborate plan to allow Jonathan to secretly communicate with David regarding Saul's plans to kill David:
18 Then Jonathan said to David, “Tomorrow is the New Moon feast. You will be missed, because your seat will be empty. 19 The day after tomorrow, toward evening, go to the place where you hid when this trouble began, and wait by the stone Ezel. 20 I will shoot three arrows to the side of it, as though I were shooting at a target. 21 Then I will send a boy and say, ‘Go, find the arrows.’ If I say to him, ‘Look, the arrows are on this side of you; bring them here,’ then come, because, as surely as the Lord lives, you are safe; there is no danger. 22 But if I say to the boy, ‘Look, the arrows are beyond you,’ then you must go, because the Lord has sent you away. 23 And about the matter you and I discussed—remember, the Lord is witness between you and me forever.”
Two days later they execute their plan, and once Jonathan sends his assistant away, David comes out from his hiding place and says his farewell to Jonathan:
41 After the boy had gone, David got up from the south side of the stone and bowed down before Jonathan three times, with his face to the ground. Then they kissed each other and wept together—but David wept the most.
What was the purpose of their secret plan, given that David and Jonathan talked face-to-face immediately afterwards? Why didn't Jonathan simply tell David the bad news in person and skip the archery charade?