The covert of the hill - Probably a defile or glen, literally a “secret place,” as in 1 Samuel 19:2. She was riding down into this glen from one side, while David and his men were descending the opposite hill. It is perhaps mentioned that she came by this “secret place,” because she chose this path to escape the observation of her husband or of anyone else.
Related Commentaries of 1 Samuel 25:20
1 Samuel 25:20
20 And it was so, as she rode on the ass, that she came down by the covert of the hill, and, behold, David and his men came down against her; and she met them.