2 Samuel 8-9; 1 Chronicles 18
God was with David and as a result, King David defeated the Philistines, Moabites, as well as Hadadezer king of Zobah and the Arameans of Damascus who came to assist Hadadezer. God gave David great victory in battle at every turn. David took the gold, silver, and bronze won from battle and that was given to him as tribute and dedicated those precious articles to the Lord. He also placed garrisons in Edom with the Edomies becoming subject to David.
Most importantly, the text declares that David ruled the people righteously, doing what was just and right for all his people. A specific element of this kindness was demonstrated in David keeping a promise to the house of Saul. David asked if there was anyone left in the house of Saul that he may show kindness to on behalf of Jonathan. Ziba, a servant of the house of Saul was found and summoned before David. David asked Ziba if there was anyone still alive from the house of Saul to whom he could show kindness. Ziba responded that Mephiboshet, a son of Jonathan, who was lame in both feet was still alive.
David summoned Mephibosheth and told him not to be afraid as he was going to keep his promise to Jonathan and would show kindness to Mephibosheth by restoring to him all the land that belonged to Saul. Furthermore, he would always eat at the table of David.