The answers I glanced at were thoughtful and insightful. My whole hermeneutic pushes different buttons in me.
My basic hermeneutic is that each and every Koine Greek character inscribed on papyrus by the authors of the NT was intended to show, that by "fulfilling," typologically, metaphorically and Platonically, every aspect of the Tanach and other then extant Jewish scripture, prove that Jesus was indeed "the Hope of Israel." The fourth canonical gospel makes this intention explicit:
[Jhn 20:30-31 NKJV] 30 And truly Jesus did many other signs in the presence of His disciples, which are not written in this book; 31 but these are written that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in His name.
[Isa 29:18 NKJV] 18 In that day the deaf shall hear the words of the book, And the eyes of the blind shall see out of obscurity and out of darkness.
This is the design of the gospel. Paul says the same:
[Rom 10:5-11 NKJV] 5 For Moses writes about the righteousness which is of the law, "The man who does those things shall live by them." 6 But the righteousness of faith speaks in this way, "Do not say in your heart, 'Who will ascend into heaven?' " (that is, to bring Christ down [from above]) 7 or, " 'Who will descend into the abyss?' " (that is, to bring Christ up from the dead). 8 But what does it say? "The word is near you, in your mouth and in your heart" (that is, the word of faith which we preach): 9 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. 10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation. 11 For the Scripture says, "Whoever believes on Him will not be put to shame."
Notice these "then you will know" prophecies:
[Isa 49:23 NKJV] 23 Kings shall be your foster fathers, And their queens your nursing mothers; They shall bow down to you with [their] faces to the earth, And lick up the dust of your feet. Then you will know that I [am] the LORD, For they shall not be ashamed who wait for Me."
[Eze 20:38 NKJV] 38 "I will purge the rebels from among you, and those who transgress against Me; I will bring them out of the country where they dwell, but they shall not enter the land of Israel. Then you will know that I [am] the LORD.
[Zec 2:9, 11 NKJV] 9 "For surely I will shake My hand against them, and they shall become spoil for their servants. Then you will know that the LORD of hosts has sent Me. ... 11 "Many nations shall be joined to the LORD in that day, and they shall become My people. And I will dwell in your midst. Then you will know that the LORD of hosts has sent Me to you.
[Zec 4:9 NKJV] 9 "The hands of Zerubbabel Have laid the foundation of this temple; His hands shall also finish [it]. Then you will know That the LORD of hosts has sent Me to you.
[Jhn 8:28 NKJV] 28 Then Jesus said to them, "When you lift up the Son of Man, then you will know that I am [He], and [that] I do nothing of Myself; but as My Father taught Me, I speak these things.
So in my hermeneutic, when trying to understand the NT, I always resort to the OT, and ask myself, "Of what OT passage is this overtly or "as a shadow" is this passage the fulfillment?"
Paul said that the sabbath, the holy days, etc. were all "fulfilled" by Christ and they, in themselves, exist only now for us to ponder and see Christ. Moses didn't give the bread from heaven, Jesus is the Bread from Heaven!
Many of the fulfillments are identified in the NT and are quite remarkable, such as this:
[Jhn 3:14-15 NKJV] 14 "And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, 15 "that whoever believes in Him should not perish but have eternal life.
Nice! Great fit!
Some seem soooo contrived as to be potentially embarrassing:
[Mat 2:23 NKJV] 23 And he came and dwelt in a city called Nazareth, that it might be fulfilled which was spoken by the prophets, "He shall be called a Nazarene."
The only relationship this passage bears with the passage it "fulfills" is the general "shape" of the events, and by the thin thread of the commonality of the Hebrew root of "Nazareth" with the Hebrew root of the word "Nazirite." Jesus was accused of being a "winebibber" because he attended parties and had a glass.
My point is that we have to locate the OT (or other extant Jewish source) background of each and every passage to really understand the prophetic significance of a passage. That is, in a very, very real sense, the NT scriptures' raison d'etre.
End of introduction. Here's the background:
[Zec 13:7 KJV] 7 Awake, O sword, against my shepherd, and against the man [that is] my fellow, saith the LORD of hosts: smite the shepherd, and the sheep shall be scattered: and I will turn mine hand upon the little ones.
And here is the fulfillment:
[Mat 26:31 KJV] 31 Then saith Jesus unto them, All ye shall be offended because of me this night: for it is written, I will smite the shepherd, and the sheep of the flock shall be scattered abroad.
Matthew has done his job. NO ONE should doubt Matthew's objective in writing this "fulfillment." He even says, "for it is written." "That it might be fulfilled" and "for it is written" are billboards, calling one's attention that he wants the reader to see the intertextuality and accept it as "proof" that Jesus was the Hope of Israel, the Son of God and the Savior of the Jewish People. Matthew, like all the apostles, were blindsided by the idea that the objective was much larger than the regeneration of the covenantally dead diaspora of Israel. That would be introduced by Peter but elaborated as seven "secrets" by Paul.
It wasn't described by Matthew as a command but rather as a divinely declared inevitability. The Messiah's sheep would be scattered as the Messiah was smitten.