Wikipedia
According to the Books of Samuel of the Tanakh, Mephibosheth ( Bib Heb: , Trans: Mefivoshet, Məp̄îḇṓšeṯ ; meaning "from the mouth of shame" or "from the mouth of god Bashtu") or Merib-baal (Bib Heb: , Trans: Meriv-Ba'al, Mərîḇ-Báʻal) is the son of Jonathan, and grandson of King Saul,.
According to the biblical narrative (2 Sam. 4:4), Mephibosheth was five years old when both his father and grandfather died at the Battle of Mount Gilboa. When the report about the deaths of Saul and Jonathan came from Jezreel, Mephibosheth’s nurse took him and fled in panic. In her haste, the child had fallen, or been dropped upon fleeing. Since then, he was unable to walk. For some years thereafter, Mephibosheth lived in the house of Machir the son of Ammiel at Lo-debar in the land of Gilead. King David learned this from Ziba, a former servant in Saul’s house. In order to fulfill his covenant with Jonathan, David wished to exercise loving-kindness toward anyone “left over of the house of Saul.”
After David had subdued all the adversaries of Israel, Mephibosheth was brought before David, and when the king explained that it was his desire to exercise loving-kindness toward Mephibosheth by returning to him “all the field of Saul” and by having him “eat bread at my table constantly,” Mephibosheth responded humbly: “What is your servant, that you have turned your face to the dead dog such as I am?” However, in keeping with David’s determination in the matter, Ziba and all those dwelling in his house (including 15 sons and 20 servants) became servants to Mephibosheth, who was given Saul’s property. He thereafter resided in Jerusalem and constantly ate at the table of the king.
When David fled from Jerusalem because of Absalom’s conspiracy, he was met by Ziba, who provided him with supplies. Answering David’s inquiries as to the whereabouts of Mephibosheth, Ziba claimed that Mephibosheth was in Jerusalem preparing to receive the kingship back. In response, David awarded Ziba all of Mephibosheth's estate (2 Sam. 16:1-4). When Mephibosheth came to meet David upon the king’s return to Jerusalem, the account saying “he had not attended to his feet nor had he attended to his mustache nor had he washed his garments from the day that the king went away until the day that he came in peace.” Mephibosheth explained that Ziba, his servant, had tricked him and then slandered him to the king. Mephibosheth sought that David would see the matter in its true light. David evidently recognized Mephibosheth’s innocence, and that he had remained loyal. David thus altered his first decree to give Mephibosheth and Ziba a share in the field. However, Mephibosheth was content with the kings return and suggested that Ziba just receive the whole lot.
When the Gibeonites sought the death of Saul’s descendants to atone for that king’s evil attempt against them, David again showed kindness to Mephibosheth because of the oath of Jehovah between David and Jonathan. So he spared Mephibosheth's life by refusing to hand him over to the Gibeonites. Though the Hebrew Bible provides no further information about Mephibosheth, Saul’s family continued in existence to a later generation through Mephibosheth’s son Mica (Micah).