That does NOT answer my question. When was David ever promised that he would sit at God's right hand?It's easy to see RR in Psalm 89:13 that God's right arm is associated with strength and might.
Psalm 89:21,25, show that God's right arm strengthens David, and David uses his right arm in a show of strength.
Saying that God's right arm represents strength is something else entirely.
He was Joseph's adopted son. How is he ruled out?And this point knocks Jesus out of contention since he was not the fruit of a male descendant of David. Isaiah 11:1 brings home this point since the shoot, stump, root, branch, and fruit must all be male. Mary has no part in any of this.