1 Samuel 30:6-10

30:6 David was very upset, for the men were thinking of stoning him; each man grieved bitterly over his sons and daughters. But David drew strength from the Lord his God.

30:7 Then David said to the priest Abiathar son of Ahimelech, “Bring me the ephod.” So Abiathar brought the ephod to David. 30:8 David inquired of the Lord, saying, “Should I pursue this raiding band? Will I overtake them?” He said to him, “Pursue, for you will certainly overtake them and carry out a rescue!”

30:9 So David went, accompanied by his six hundred men. When he came to the Wadi Besor, those who were in the rear stayed there. 30:10 David and four hundred men continued the pursuit, but two hundred men who were too exhausted to cross the Wadi Besor stayed there.