A fountain - Probably, the fine spring Ain-Jalud. It is impossible to say what the special circumstances were which led to the struggle between Israel and the Philistines taking place so far north as the plain of Jezreel. Possibly it was connected with some movements of the Aramaic tribes to the north of Palestine. See 2 Samuel 8.
Related Commentaries of 1 Samuel 29:1
1 Samuel 29:1
1 Now the Philistines gathered together all their armies to Aphek: and the Israelites pitched by a fountain which is in Jezreel.