Charles Ellicott Commentary 1 Chronicles 11:15

"And three of the thirty chief men went down to the rock to David, into the cave of Adullam; and the host of the Philistines were encamped in the valley of Rephaim." — 1 Chronicles 11:15 (ASV)

Now three of the thirty captains. —Literally, and a three out of the thirty chiefs went down; a mode of description which appears to distinguish this trio from the former (1 Chronicles 11:11–14). The form of the verb, however, connects this exploit with the same war. (Compare 2 Samuel 23:13–17.)

To the rock. —’ Al haç-çûr (later use of ‘ al, “on”). Samuel has “at (or towards) harvest,” ‘el qaçir. In Hebrew writing the phrases are very similar. Our phrase looks like a correction of that in Samuel. At any rate, the Syriac, Targum, Arabic, and probably the Septuagint, read qaçir in the manuscripts of Samuel. Here the Septuagint has “to the rock;” Syriac omits the phrase.

Cave of Adullam. —See 1 Samuel 22:1.

Encamped. — Were camping.

Valley of Rephaim. —See Joshua 15:8, Note. It lay south-west of Jerusalem, in the direction of Bethlehem. It may have got its name from the aboriginal Rephaim, Deuteronomy 3:11 (Authorised Version, giants), Joshua 17:15. It was a rich corn land (Isaiah 13:5). (Compare 1 Chronicles 11:13.)