1 Samuel 30:6-10

6Further, David was greatly distressed because the people spoke of stoning him, for all of them were embittered, each man for his sons and daughters. But David felt strengthened and encouraged in the Lord his God.

7David said to Abiathar the priest, Ahimelech’s son, “Please bring me the ephod.” So Abiathar brought him the ephod.

8David inquired of the Lord, saying, “Shall I pursue this band [of raiders]? Will I overtake them?” And He answered him, “Pursue, for you will certainly overtake them, and you will certainly rescue [the captives].”

9So David went, he and the six hundred men who were with him, and came to the brook Besor; there those [who could not continue] remained behind.

10But David pursued [the Amalekites], he and four hundred men, for two hundred who were too exhausted to cross the brook Besor stayed behind.