Albert Barnes Commentary 2 Samuel 9:10

"And thou shalt till the land for him, thou, and thy sons, and thy servants; and thou shalt bring in [the fruits], that thy master`s son may have bread to eat: but Mephibosheth thy master`s son shall eat bread alway at my table. Now Ziba had fifteen sons and twenty servants." — 2 Samuel 9:10 (ASV)

Fifteen sons... — See 2 Samuel 19:17, marginal reference.