Adam Clarke on 1 Samuel 29:1

To Aphek - This was a place in the valley of Jezreel, between Mounts Tabor and Gilboa.

Pitched by a fountain - To be near a fountain, or copious spring of water, was a point of great importance to an army in countries such as these, where water was so very scarce. It is supposed, as William of Tyre says, that it was at this same fountain that Saladin pitched his camp, while Baldwin, king of Jerusalem, pitched his by another fountain between Nazareth and Sephoris; each being anxious to secure that without which it was impossible for their armies to subsist.