Jamieson, Fausset and Brown on 1 Samuel 23:19-23

19-23. Then came up the Ziphites to Saul to Gibeah, saying, Doth not David hide himself with us?--From the tell of Ziph a panorama of the whole surrounding district is to be seen. No wonder, then, that the Ziphites saw David and his men passing to and fro in the mountains of the wilderness. Spying him at a distance when he ventured to show himself on the hill of Hachilah, "on the right hand of the wilderness," that is, the south side of Ziph, they sent in haste to Saul, to tell him of the lurking place of his enemy [Van De Velde].