John Gill Commentary 2 Samuel 16:3

"And the king said, And where is thy master`s son? And Ziba said unto the king, Behold, he abideth at Jerusalem; for he said, To-day will the house of Israel restore me the kingdom of my father." — 2 Samuel 16:3 (ASV)

And the king said, and where [is] thy master's son ?
&c.] The son of Saul, who was Ziba's master, meaning Mephibosheth:

and Ziba said unto the king, behold, he abideth at Jerusalem ;
as there was reason for it, since he was lame of both his feet, (2 Samuel 9:13) , though he could have rode upon an ass, and followed the king, as he proposed to do; but his servant deceived him, and carried off the asses to serve a purpose for himself, see (2 Samuel 19:26) ;

for he said, today shall the house of Israel restore unto me the
kingdom of my father ;
his father Saul; which was far from his thoughts; and a most wicked suggestion of his servant to blacken his character, and get his estate from him; nor was there the least probability of the kingdom coming to him, but all the reverse; for let it go how it would with David, Absalom, and not Mephibosheth, stood fair for the kingdom.