1 Samuel 22:2-4

New International Version - UK

² All those who were in distress or in debt or discontented gathered round him, and he became their commander. About four hundred men were with him.

³ From there David went to Mizpah in Moab and said to the king of Moab, ‘Would you let my father and mother come and stay with you until I learn what God will do for me?’ ⁴ So he left them with the king of Moab, and they stayed with him as long as David was in the stronghold.