2 Samuel 9:3

And the king said, Is there not yet any of the house of Saul, that I may shew the kindness of God unto him? And Ziba said unto the king, Jonathan hath yet a son, which is lame on his feet.

Cross-reference

2 Samuel 9:7 records David fulfilling his promise to show kindness, restoring land and providing at his table.

2 Samuel 9:13 concludes the story, noting Mephibosheth ate at David's table and was lame in both feet, confirming his condition.

2 Samuel 4:4 Historical context

2 Samuel 4:4 provides the backstory of Mephibosheth's lameness, explaining why Ziba describes him as lame in feet.

In 2 Samuel 19:26, Mephibosheth later references his lameness as reason he couldn't accompany David, confirming his condition.

In 1 Samuel 20:14-17, Jonathan bound David to show kindness to his house — here David fulfills that covenant by seeking Mephibosheth.