And the king sware, and said, As the LORD liveth, that hath redeemed my soul out of all distress,
David swore a solemn oath by the living Lord who had delivered his soul from every distress. He made this oath at the moment he confirmed that Solomon would succeed him as king. By so swearing he acted to carry out the succession he had previously promised. The oath therefore bound his declaration of Solomon's kingship to his testimony that the Lord had redeemed him out of all distress.
David swore a solemn oath by the living Lord who had delivered his soul from every distress. He made this oath at the moment he confirmed that Solomon would succeed him as king. By so swearing he acted to carry out the succession he had previously promised. The oath therefore bound his declaration of Solomon's kingship to his testimony that the Lord had redeemed him out of all distress.