Psalm 110 is famous as one of the Psalms that clearly points to Christ and is the most quoted Psalm in the New Testament. In this Psalm David writes
The Lord says to my Lord:
“Sit at my right hand,
until I make your enemies your footstool.
Here, David introduces him to the Lord who speaks to his lord. Now, when we see the phrase “The Lord” in the Old Testament, it is a replacement for the divine name YHWH. The Jews believed the divine name was so holy that it should not be uttered by sinful human lips so they replaced it with the word Adonai (Lord). So YHWH speaks to David’s Lord. The second use of “lord” is not on its own a reference to YHWH. However, in this context it is worth noting that David say at the top of the pile. He was the king over God’s people, answerable to no-one. He was not a vassal of anyone else but freely ruled over a small but growing empire. So was David’s boss? Well it was God himself. Who then is David referring to in the Psalm? The New Testament writers conclude that it is Jesus. Jesus is David’s Lord therefore making him God. The idea that one who can call themselves Lord can refer to another who is also Lord without any sense of rivalry or division is part of the Biblical argument that points to God as Trinity.
Jesus is the one who sits enthrones and exalted and the Father is at work defeating his enemies so that they are forced to bow and Jesus as king places his feet on them demonstrating that they are completely subject to him.
This is important because we have been talking about how we respond to our enemies when they slander us, attack us and try to cause trouble against us? Well, a significant part of the answer is here in these verses. My enemies are really Jesus’ enemies. In so far as their sin makes them want to undermine the work of the Gospel, in so far as they pursue personal ambition at the expense of love and grace, they seek to impose Christ’s rule and Christ’s mission.
David recognises this when he declares in Psalm 51:4 when he says
Against you, you only, have I sinned
and done what is evil in your sight,
so that you may be justified in your words
and blameless in your judgement.
This is important because it means that when I seek vengeance for myself, when I hold onto my anger until it turns into bitterness then I am taking away from Christ’s right to judge and to seek satisfaction from his enemies.
Similarly, when someone comes seeking forgiveness from me and from God and I withhold it then I am choosing to disagree with Christ’s response. I am saying that whatever Christ’s verdict against the person, I refuse to acknowledge it and carry out my own judgement.
In other words, there are two ways in which I might dishonour Christ here. I dishonour Christ by choosing to side, defend and partner with people who are In opposition to Christ. I am choosing to align myself with his enemies. However, I also dishonour him when I fail to forgive those who have repented because I choose to stand against those that now belong to Christ.
Psalm 110 therefore reinforces the importance of forgiveness. I know where I have come from, Christ has forgiven and redeemed me. I know where I am going, he has promised to hold me fast in his faithful love. Therefore when Christ chooses to show loving kindness in saving others, I must stand with him.
 Psalm 110:1