In some versions (Contemporary English Version, New American Bible) a new section heading is placed before this verse. But most have only a new paragraph here.

The people of Israel, which occurs twice in this verse, is literally “the sons of Israel” as in verses 4 and 6 above.

Heard: this is not to be understood in the sense that the Philistines actually heard the Israelites gathering at Mizpah. Rather they heard a report of some unknown person or persons who were aware of the Israelites movements. The same verb occurs at the end of this verse with the same meaning. In both cases some languages may require a restructuring like the following: “Someone told the Philistines” and “someone reported to the Israelites….”

Lords of the Philistines: see the comments on 5.8.

The verb went up reflects the fact that the Philistines lived on the coast and had to go up to a higher altitude to attack the Israelites. Many translations omit this aspect of meaning and say simply that the Philistines “marched out against Israel” (New Jewish Publication Society’s Tanakh) or “marched against them” (Revised English Bible). If the receptor language naturally uses verbs like “go up” to describe movement from one place to another of a different elevation, then they may be used in translation; otherwise such verbs should be avoided.

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on the First and Second Books of Samuel, Volume 1. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here .