John Gill Commentary 2 Samuel 16:4

"Then said the king to Ziba, Behold, thine is all that pertaineth unto Mephibosheth. And Ziba said, I do obeisance; let me find favor in thy sight, my lord, O king." — 2 Samuel 16:4 (ASV)

Then said the king to Ziba, behold, yours are all that
pertain to Mephibosheth
Being forfeited to the king by an overt act of treason as they had been before by the rebellion of Ishbosheth, but had been graciously restored to Mephibosheth; and had it been true what Ziba suggested, it would have been a righteous thing to have taken them from him; though it seems to be too hasty a step in David to take and give them away without further inquiry:

and Ziba said, I humbly beseech you that I may find grace in your
sight, my lord, O king ;
he had found favour already, but seems not to be sufficiently thankful for it, and satisfied with it, but craved more and other favours, when opportunity should serve.