In those days: literally “And it happened [traditionally, It came to pass] in those days.” But since some time has passed, it is reasonable to translate this transition verb phrase as “Some time later” (Good News Translation) or simply “Later” (New Century Version). Another possibility is “It then happened that…” (New Jerusalem Bible).

The word translated forces is often rendered “camp, host, army.” Here it refers to the military troops at the disposal of the Philistine leaders.

Achish: see the comments on 21.10.

Understand: literally “To know you know.” This is a very emphatic statement indicating that what follows is to be clearly understood: “Be sure of this” (Knox); “You must understand” (Anchor Bible); “You know, of course” (New Jewish Publication Society’s Tanakh, New Revised Standard Version).

The army: in Hebrew this is the same word as that rendered forces in the first half of this verse. Instead of the word in the army, found in the Masoretic Text, the Septuagint says “into battle.” Compare New Jerusalem Bible, “It is understood that you and your men go into battle with me.” Critique Textuelle de l’Ancien Testament supports the Masoretic Text, giving it a {B} rating. The difference in meaning between the Hebrew and the Greek texts is not very important for translation purposes.

A single manuscript, from Qumran, has the name “Jezreel” at the end of this verse; this is the basis for the New American Bible translation “you and your men must go out on campaign with me to Jezreel” (see 29.1).

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 .