Other OT verses with a similar plural theme:
Genesis 1:26 Let US make man in OUR image
Genesis 3:22 Behold, the man has become like one of US, knowing good and evil
Isisah 6:8 Whom shall I send, and who will go for US?
I've also found the following in "Systematic Theology" by Wayne Grudem, and recommend it as a highly useful text.
Start Quote:
In Psalm 110:1 David says
"The Lord says to my lord: "Sit at my right hand until I make your enemies a footstool for your feet"
Jesus rightly understands that David is referring to two separate persons as "Lord"
See Matt. 22:41-46:
"While the Pharisees were gathered together, Jesus asked them, "What do you think about the Christ? Whose son is he?"
"The son of David," they replied.
He said to them "How is it then that David, speaking by the Spirit, calls him 'Lord'? For he says,
"The Lord said to my Lord, sit at my right hand...."
If then David calls him 'Lord', how can he be his son?"
So who is David's "Lord" if not God himself? And who could be saying to God, "Sit at my right hand" except someone else who is also fully God? From a NT perspective we can paraphrase: "God the Father said to God the Son, "Sit at my right hand". But even without the NT teaching on the Trinity, it seems clear that David was aware of a plurality of persons in one God.....
End Quote.
So perhaps those claiming Paul was a pagan and mendaciously brought the concept of a triune God into Christianty should make like the Pharisees and
"never dare ask a question of Jesus again"