Ezel
Ezel is a stone — a fixed landmark — near Saul's residence, named once in scripture. It is the place Jonathan gives David as the meeting-point at which the result of Jonathan's probe of Saul's intent will be communicated.
A meeting-stone for David and Jonathan
The instruction is part of Jonathan's contingency plan in the long conversation of 1 Samuel 20: "And on the third day, you will go down quickly, and come to the place where you hid yourself when the business was in hand, and will remain by the stone Ezel" (1 Sam 20:19). The chronology is Hebrew counting — "the third day" is the day after tomorrow. The location is fixed by reference to a previous hiding-place, the stone serving as an unambiguous on-the-ground marker that both men can find without further description. Nothing more is recorded of Ezel beyond this single appearance as a private rendezvous in the days when David's life depended on Jonathan reading Saul correctly.