These verses seem to be addressed to God the Father, the Creator of the heavens and the earth rather than to the Messiah. How can the writer of Hebrews quote that as evidence that the Messiah is superior to any angelic being?
Rather than looking at each of the quotes in question, it will be helpful to examine how the New Testament apostles interpreted the Old Testament prophets. Some of their prophetic utterances were, without doubt, predictive in nature, such as when Matthew quotes the prophecy of Micah predicting the birthplace of Messiah at Bethlehem (Matthew 2:1-6). In this sense, we can say that Jesus fulfilled what was spoken by the prophet. But there are also other passages they quote where it is not so much that Messiah fulfilled a certain prediction, as much as he filled full something in Israel’s history. An example of that can be seen in how Matthew quotes Jeremiah’s prophecy in Matthew 2:17-18 of Rachel weeping for her children. The context in Jeremiah demonstrates clearly that he is describing the carrying away of Judah during the Babylonian Captivity. How then can Matthew quote it as being fulfilled at the slaughter of the Bethlehem’s Infants? Because Matthew is saying that this event is now “filled-full” in the light of the Messiah. That is, in the events surrounding the Messiah, the real meaning of this period in Israelite history can be understood.
The simplest way to say it is Messiah is the key that unlocks all of Scripture! We can see this demonstrated in the Upper Room when the risen Lord took the eleven through each division of the Hebrew Bible (Law, Prophets, Psalms) and “opened their minds to understand the Scriptures” (Luke 24:45). That didn’t mean that he familiarized them with Holy Scripture—as Jews they were thoroughly immersed in Holy Scripture from birth. Rather, it means that he showed them how He was now the interpretive key to all they had known in Holy Scripture. He not only fulfilled certain predictions made by the Holy Prophets hundreds of years before his birth, He filled full all of its history so that He now gives new meaning to all that was written.
But getting back to the whole of this section, the writer’s intent in these passages is to demonstrate that Messiah, in every way, is superior to the angelic world. This is, as we have already seen, important teaching for his Jewish readers, but it carries relevance today as well in that some of cults hold that Jesus of Nazareth is equal to other angelic beings such as Michael or Gabriel. By quoting the Old Testament seven times, the writer not only proves that Jesus of Nazareth is superior to the angels, he also sounds out a prevalent theme in this letter: that He is superior to the Old Covenant since it was mediated to Israel by means of angels.