When you have stayed three days, you shall go down quickly, and come to the place where you did hide yourself when the business was in hand, and shall remain by the stone Ezel.
The shooting of arrows was probably just a practical way to signal David. Jonathan reminded David of their agreement as they parted (1 Samuel 20:23; cf. Genesis 31:48-53). [Note: For discussion of a minor textual problem in 1 Samuel 20:23, see Emunah Finkelstein, "An Ignored Haplography in Samuel," Journal of Semitic Studies 4:4 (October 1959):356-57.] 