1 Chronicles 11:15
Now three of the thirty captains went down to the rock to David, into the cave of Adullam; and the host of the Philistines encamped in the valley of Rephaim. Now three of the thirty captains went down to the rock to David, into the cave of Adullam; and the host of the Philistines encamped in the valley of Rephaim.
The verse belongs to the fuller account of David becoming king over all Israel, when the tribes gathered at Hebron to acknowledge him as king. That larger account is framed around God's purpose to bring David to the throne through the political changes that left him as king. Within that assembly the chapter contributes the report of the gathered fighting men and the three-day festival.
Within the record of David's work and the division of his armies, the verse records three of the thirty mighty men going down to David at the rock in the cave of Adullam while the host of the Philistines encamped in the valley of Rephaim. This record parallels the same record in Samuel apart from genealogies. The record gives lessons on what made men truly mighty, on David's virtues and mistakes, and on God's mercy and guidance.