This passage occurs in the RCL, Year 1, Advent IV, most recently December 18, 2016.
Summary: This passage teems with Old Testament allusions. These allusions make it clear that Christ is to be exalted. Furthermore, they make it clear that Joseph is a special person. I appreciate why the church has so adored Mary; I think Joseph is often overlooked. As Rev. Daniel Clark said to me while he was serving at my parish as a Vicar: Joseph is the blue collar bible character; a quiet, humble and hard-working person that Scripture overlooks!
γενεσις (lit. 'genesis', meaning "beginning" or "birth", 1:18) Matthew uses this word twice in his first chapter (also 1:1). He could have picked simpler words for giving birth, as he does in vs. 25. I believe he used this word intentionally to connect back the Old Testament opening creation passages. The first book but also the first word of the Hebrew Bible is "beginnings" (in Greek -- Genesis). Furthermore, like in the Old Testament, Matthew seems to offer two creation accounts, first the grand and then second, the detailed version.
To have more fun with this connection: I believe Matthew in vs 1:1 here riffs on Genesis 2:4, much like John's Gospel opens with a riff on Genesis 1:1. Matthew employs the the phrase "βιβλος γενεσωες" found only in Genesis 1:1. Both creation accounts are picked up by the New Testament!
υιος Δαυιδ (meaning "son of David", 1:20) When this phrase is used elsewhere in the Old Testament (Jeremiah 13:13 ; 2 Chronicles 32:33), it does not refer to the Jews or all of the Hebrews. It refers to the ancient kings of Israel. Matthew here is calling Joseph a king.
οναρ (meaning "dream", 1:20) I am embarrassed to admit that I never saw this connection until some pastors showed this to me last week -- both the Old Testament Joseph and the New Testament Joseph have dreams...and go to Egypt! I wonder if I didn't discover this earlier because the Greek version of the Old Testament uses a different word for dream. Regardless, a cool connection.
Iησους (lit. 'Jesus', 1:21) This is the name to be given to the baby born to Mary. It is the Old Testament name Joshua. Names often change when they move across cultures (Robert=Roberto in Spanish), so believe it or not, Joshua and Jesus are the same name in Hebrew. Joshua's name means "The LORD saves" and his job is to lead the people across the river Jordan into the promised land. Jesus will save the people, get baptized in the river Jordan and lead the people into the promised land. We miss that connection in English that would have been clear to Joseph and Mary: They are to name their child "the Lord saves" for he will save the people from their sins.
Εμμανουηλ (lit. 'Emmanuel', meaning "God is with us", 1:23) Although he is declared here to be "God is with us" Jesus will not assume this title during his ministry of teaching and healing. Why is this? I would argue because he must first die and rise in order to be Emmanuel. At the end of Matthew's Gospel, Jesus declares "I am with you." However, the literal Greek here is "I with you am"; "I am" is the ancient name of God. So here Jesus expands the title of God to include -- at its heart -- with you. He then takes on the name Immanuel, but only after the cross and empty tomb.
μη φοβηθης (meaning "do not be afraid", 1:20) Little side note on the Greek. Although the English translators translate this the same way they translate the words of Gabriel to Mary (do not be afraid), it is slightly different in the Greek. It is the same verb (φοβοω), but it is in the passive voice for Joseph and the active voice for Mary. Technically then the translation for Mary should be "Do not fear" and for Joseph "Do not be afraid." This is not very different, really. But what is interesting is that when the passive construction is used in the LXX translation of the Old Testament, it often has an element (further suggested by the words' meaning in Homeric Greek, I would argue) of "Do not flee." Perhaps the angel is telling Joseph, "Don't go anywhere!"