The history does not record any instance of Nahash’s kindness to David, but the enmity of the house of Nahash against Saul may have disposed him favorably toward Saul’s enemy David, and if there was any family connection between David’s house and Nahash 2 Samuel 17:25 this may have increased the friendship.
Related Commentaries of 2 Samuel 10:2
2 Samuel 10:2
2 Then said David, I will shew kindness unto Hanun the son of Nahash, as his father shewed kindness unto me. And David sent to comfort him by the hand of his servants for his father. And David's servants came into the land of the children of Ammon.