This verse perhaps provides a clue about the meaning of the word Hebrews in some of the other verses in this passage. Here it is quite clear that these were Israelites who had been with the Philistines, that is, who had been a part of the Philistine fighting force. Contemporary English Version refers to them as “hired soldiers.” Compare 13.7.

Before that time: literally “yesterday and the day-before-yesterday.” See the same Hebrew idiom in 10.11. Similar expressions are also found in 19.7 and 21.5.

Even they also turned: this is a translation based on the Septuagint and is accepted by nearly all interpreters. The difficulty with this translation, however, is that it implies that there were others who previously had also defected from the Philistines to the Israelites. At least that seems to be the implication of the words “they also.” But the text says nothing about others having turned to be with the Israelites.

The Masoretic Text says “round about, and they also.” In Hebrew the word “round about” is an adverb, indicating that the Hebrews had been camped around the camp of the Philistines. The following translation reflects the recommendations of Critique Textuelle de l’Ancien Testament, which gives a {C} rating to the Masoretic Text: “And the Hebrews who had previously sided with the Philistines and had gone up to their camp and camped around the Philistines, these Hebrews also joined with the Israelites who had joined Saul and Jonathan.”

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 .