Psalm 110 Part 1  

This Messianic Psalm is brief in the number of its words but great in the weight of its thought. It is the most referred to psalm in the NT! Jesus quoted it seven times! Paul quoted it nine times, Luke 6 times, John and Peter both once plus there are other allusions to it. 

This psalm cannot be written both by David and about him. Jesus settled its significance on two separate occasions. David prophetically revealed the words of Yahweh (the LORD) to the Messiah, David’s Lord. This is clear not only from the context but especially by how this verse is quoted in the NT. Jesus quoted it in Matthew 22:43-45 and Luke 22:69, showing how David called the Messiah “Lord” – recognizing that the Messiah was greater than David himself. Peter quoted it on the Day of Pentecost, spelling out the implications, explaining how David prophesied the deity and ascension of Jesus (Acts2:34-35). 

Paul referred to it in 1Cor15:25, explaining the rule and dominion of Jesus the Messiah. He also quotes it in Heb1:13, referring to the superiority of Jesus the Messiah over any angel, and in Heb10:13, explaining the rule and dominion of Jesus the Messiah.  
The fact that Yahweh – the LORD, the covenant God of Israel – spoke to one that David himself called Lord (Adonai) demonstrates that both Yahweh and Adonai, mentioned in this verse, are God! 

Normally, when Yahweh is mentioned without a specific connection to the person of the Son or the Holy Spirit, we assume it refers to God the Father. Therefore, here God the Father is speaking to the Messiah, God the Son. This person can only be a divine Messiah, who is Jesus Christ.  
Yahweh (God the Father) spoke to the Messiah (God the Son), telling Him to take His enthroned place (Eph1:20, Heb8:1) until the Father provided the victory for the Son. He was then to sit at the favoured place, at His right hand, until the grand result of the complete divine victory which is certain to follow through the gospel (the rod of His strength, that came out of Israel to the world v2.) AWESOMENESS! TBC