'Grandfather' in the Bible

“Don’t be afraid,” David said to him, “since I intend to show you kindness because of your father Jonathan. I will restore to you all your grandfather Saul’s fields, and you will always eat meals at my table.”

Then the king said, “And where is your master’s son [Mephibosheth]?” Ziba said to the king, “Behold, he remains in Jerusalem, for he said, ‘Today the house of Israel will give me back the kingdom of my father.’”

After all, there was no one in the entire house of my grandfather who did not deserve death from my lord the king. But instead you allowed me to eat at your own table! What further claim do I have to ask the king for anything?"