John Wesley on 1 Samuel 22:4

Hold - In holds; the singular number being put for the plural; as is frequent; that is, as long as David was forced to go from place to place, and from hold to hold, to secure himself: for it concerned David to secure his father, and he did doubtless secure him for all that time; and not only while he was in the hold of Mizpeh, or of Adullam, which was but a little while.