2 Samuel 9:6

Now Jonathan, Saul’s son, had a son crippled in his feet. He was five years old when the report of Saul and Jonathan came from Jezreel, and his nurse took him up and fled. And it happened that in her hurry to flee, he fell and became lame. And his name was Mephibosheth.

Now David had passed a little beyond the summit, and behold, Ziba the young man of Mephibosheth met him with a couple of saddled donkeys, and on them were two hundred loaves of bread, one hundred clusters of raisins, one hundred summer fruits, and a jug of wine.

Now Mephibosheth the son of Saul had come down to meet the king; and he had not done anything for his feet, nor done anything for his mustache, nor washed his clothes, from the day the king departed until the day he came home in peace.

But the king spared Mephibosheth, the son of Jonathan the son of Saul, because of the oath of Yahweh which was between them, between David and Saul’s son Jonathan.