Commentary for II Samuel 23:13

וַיֵּרְד֨וּ שלשים [שְׁלֹשָׁ֜ה] מֵהַשְּׁלֹשִׁ֣ים רֹ֗אשׁ וַיָּבֹ֤אוּ אֶל־קָצִיר֙ אֶל־דָּוִ֔ד אֶל־מְעָרַ֖ת עֲדֻלָּ֑ם וְחַיַּ֣ת פְּלִשְׁתִּ֔ים חֹנָ֖ה בְּעֵ֥מֶק רְפָאִֽים׃

And three of the thirty chief went down, and came to David in the harvest time unto the cave of Adullam; and the troop of the Philistines were encamped in the valley of Rephaim.

Rashi on II Samuel