Matthew Henry Commentary 2 Samuel 16:1-4

"And when David was a little past the top [of the ascent], behold, Ziba the servant of Mephibosheth met him, with a couple of asses saddled, and upon them two hundred loaves of bread, and a hundred clusters of raisins, and a hundred of summer fruits, and a bottle of wine. And the king said unto Ziba, What meanest thou by these? And Ziba said, The asses are for the king`s household to ride on; and the bread and summer fruit for the young men to eat; and the wine, that such as are faint in the wilderness may drink. 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. 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 16:1-4 (ASV)

Ziba slandered Mephibosheth. Great men should always be wary of flatterers, and be careful to hear both sides.