The ruler from Bethlehem
What 'from of old' means of the ruler's origins, and how the priests' citation answers Herod.
Micah 5:2-5
2But you, Bethlehem Ephrathah, being small among the clans of Judah, out of you one will come out to me that is to be ruler in Israel; whose goings out are from of old, from ancient times.
3Therefore he will abandon them until the time that she who is in labor gives birth. Then the rest of his brothers will return to the children of Israel.
4He shall stand, and shall shepherd in the strength of Yahweh, in the majesty of the name of Yahweh his God: and they will live, for then he will be great to the ends of the earth.
5He will be our peace when Assyria invades our land, and when he marches through our fortresses, then we will raise against him seven shepherds, and eight leaders of men.
Matthew 2:1-6
1Now when Jesus was born in Bethlehem of Judea in the days of King Herod, behold, wise men from the east came to Jerusalem, saying,
2“Where is he who is born King of the Jews? For we saw his star in the east, and have come to worship him.”
3When King Herod heard it, he was troubled, and all Jerusalem with him.
4Gathering together all the chief priests and scribes of the people, he asked them where the Christ would be born.
5They said to him, “In Bethlehem of Judea, for this is written through the prophet,
6‘You Bethlehem, land of Judah, are in no way least among the princes of Judah: for out of you shall come a governor, who shall shepherd my people, Israel.’ ”
What each tradition says
Rabbinic / Midrashic
Rashi explains “and his origin is from of old” with Psalm 72:17: “Before the sun his name is Yinnon.” The ruler’s origin is thus before the sun, and his name is Yinnon.
Rashi (R. Solomon ben Isaac), Rashi on Micah 5:1 — The Judaica Press Tanach with Rashi, A. J. Rosenberg trans., served by Sefaria — Commentary on Micah 5:1 (Hebrew versification; = 5:2 in English versification)
Patristic
Justin Martyr says that when the Magi came from Arabia, they told Herod they knew from a star that a King had been born, and they had come to worship him. Herod then learned from the elders that the prophet had written of Bethlehem: out of it would go forth the leader who would feed my people.
Justin Martyr, Dialogue with Trypho (ANF01. The Apostolic Fathers with Justin Martyr and Irenaeus) — Ch. 78 (on the Magi and the elders' answer to Herod)
Catholic
Haydock's commentary says the ancient Jews clearly understood this passage as referring to the Messiah. It notes that modern interpreters explain it of Zerubbabel, but adds that the expressions are too grand for him.
George Leo Haydock, George Haydock's Catholic Bible Commentary — Commentary on Micah 5:2
Orthodox
Ephraim calls Ephrata blessed, the mother of Kings, because from her sprang the Lord of diadems. He says Micah announced that this one is from everlasting, and the span of his times is not comprehended.
Ephraim the Syrian, Nineteen Hymns on the Nativity of Christ in the Flesh (NPNF-213. Gregory the Great (II), Ephraim Syrus, Aphrahat; A. E. Johnston trans.) — Hymn XVIII, stanza 11 (on Ephrata)
Reformed / Protestant
Calvin acknowledges that Christ’s divinity is proved here, but because Jews will not accept that, he prefers the plain sense: Christ will not come unexpectedly from Bethlehem, as if God had previously determined nothing about him. He thus avoids claiming the prophet directly speaks of Christ’s eternal existence.
John Calvin, Commentary on Jonah, Micah, Nahum — On Micah 5:2
Evangelical
Wesley identifies the ruler as King and sovereign, present amidst the Israel of God. By his “going forth,” Wesley means his generation: as the Son of God, equal with the Father, it is eternal.
John Wesley, Explanatory Notes upon the Old Testament — Note on Micah 5:2