Faced with the deep fears of his men, David approaches God a second time before heading into battle. This repeated inquiry is a direct response to his followers' concerns. By consulting God again, David aims to encourage his men, strengthen their resolve, and prove to them that there is no reason to fear the upcoming conflict [מצודת דוד, ביאור שטיינזלץ]. Alternatively, this second request serves a strategic purpose, allowing David to receive more precise and detailed instructions regarding the military campaign [מלבי״ם].
When God answers, He provides a detailed, three-part promise to completely reassure David and his forces. First, He commands David to physically enter the city of Keilah, urging him to do so with absolute confidence and without fear. Second, God guarantees a clear and decisive victory, promising that this triumph will be achieved miraculously through His direct intervention. Finally, God clarifies the vast scope of this success. He assures David that the victory will not be a minor skirmish against a small, local band of fighters, but rather a total defeat of the entire Philistine nation [מלבי״ם].