Some of those who hold a low view of Jesus, such as the Jehovah’s Witness and the Biblical Unitarians, try to say that Psalm 110:1 is proof positive that Jesus is no more than a man. They conclude this, because they claim their Brown-Driver-Briggs Lexicon (BDB) says that the form of adonai (H136) used does not pertain to God anywhere in the Bible. They conclude that it has to do with men only and therefore Jesus cannot be God. Notice the Scripture:
Psalms 110:1-7 KJV The LORD said unto my Lord, Sit thou at my right hand, until I make thine enemies thy footstool. (2) The LORD shall send the rod of thy strength out of Zion: rule thou in the midst of thine enemies. (3) Thy people shall be willing in the day of thy power, in the beauties of holiness from the womb of the morning: thou hast the dew of thy youth. (4) The LORD hath sworn, and will not repent, Thou art a priest for ever after the order of Melchizedek. (5) The Lord at thy right hand shall strike through kings in the day of his wrath. (6) he shall judge among the heathen, he shall fill the places with the dead bodies; he shall wound the heads over many countries. (7) he shall drink of the brook in the way: therefore shall he lift up the head.
I looked this up in my BDB Lexicon and sure enough what they claim is correct. BDB: Adonai in Psalm 110:1 refers to “human superiors.” However, they never show why. I hate taking anyone’s word for something. I like to prove what the experts say. That way I own it. Nevertheless, that door of understanding is shut to me here. What does this interpretation prove? It does not prove that Jesus is not God. It merely proves (if correct) that the office of Messiah is not an office of Deity. I have never claimed such. In fact, I have shown that this throne cannot indicate Deity, because the Lord Jesus invites us who overcome to sit with him on that throne (Revelation 3:21). This is David’s throne, which is assumed by Jesus, the Messiah, who rules over all the earth.
The other throne that Jesus rules from, however, is the throne of God (Revelation 22:1, 3), and both Jesus and the Father rule from there forever and ever (Revelation 22:5). Now, how does this relate to Psalm 110? Well, notice Psalm 110:5 above. “The Lord at thy right hand shall strike through kings in the day of his wrath.” To whom does this Scripture refer? If we take Revelation 22:1, 3 into consideration, it is Jesus who sits at the right hand of the Father (cp. Hebrews 8:1; 10:12; 12:2; 1Peter 3:22). Nevertheless, this is not the entire story. It doesn’t matter what anyone’s BDB says about this Lord, because Scribes known as the Sopherim had changed this word a few hundred years before Christ. These were guardians of the Sacred Text. Probably out of respect for the name of God, they changed to adonai some places where the tetragrammaton (YHWH) had been in the original manuscripts. One of those places is Psalm 110:5. It therefore should read: “The LORD (or YHWH) at thy right hand shall strike through kings in the day of his wrath.” There is no doubt that Psalm 110:5 is speaking of Jesus even those who hold a low view of him say this is true. However, here is another indication of plurality within the Godhead. Not only does Jesus sit on the throne of God, showing that he is God, but he is called by the name of God, YHWH, in Psalm 110:5.
However, if by chance some would say that Psalm 110:5 really indicates the Father (the Jewish Scribes known as the Sopherim didn’t think so), then the Father would be at Jesus’ right hand executing the will of Jesus! I don’t believe this would be the correct rendering, but this is the only other choice one has to keep a Scripture passage, that everyone agrees points to Jesus, from saying that Jesus is YHWH!
 Companion Bible; Appendix 32, page 31; E.W. Bullinger; The 134 Passages Where The Sopherim Altered “Jehovah” To “Adonai” The Bullinger Publications Trust, 1972.