Came down to meet. — The obvious meaning of this is that Mephibosheth came down from the high land of Jerusalem to meet the king in the Jordan valley, and in this case the following verse should be translated, “And it came to pass when Jerusalem” (meaning its inhabitants, with Mephibosheth among them) “was come to meet the king.” Some writers, however, prefer to keep 2 Samuel 19:25 as it is, and to suppose that during the rebellion Mephibosheth had taken refuge on his ancestral estate near the heights of Gibeah, and that he came thence to Jerusalem to meet David. In either case the signs of deep mourning used by Mephibosheth “from the day the king departed” were an evidence of his loyalty. The word for beard is used only for the moustache.
2 Samuel 19:24
24 And Mephibosheth the son of Saul came down to meet the king, and had neither dressed his feet, nor trimmed his beard, nor washed his clothes, from the day the king departed until the day he came again in peace.