Matthew Poole and continuators on 2 Samuel 9:10

10 Thou therefore, and thy sons, and thy servants shall till the land for him, and thou shalt bring in the fruits, that thy masters son may have food to eat : but Mephibosheth thy masters son shall eat bread alway at my table. Now Ziba had fifteen sons, and twenty servants .

i. e. That he may have wherewith to buy Food for all his Family, and all manner of provisions (which oft come under the tile of Food and Bread) necessary for himself and them.

For it is probable he had been the chief Steward to manage Saul's Lands: whereby he had great opportunities to inrich himself, which also he was very intent and resolved upon, either directly, or indirectly, as the following History of him shews; and therefore it is not strange that he was so rich.