Matthew 1:23

“Behold, a virgin shall be with child, etc.] These words are rightly applied to the virgin Mary and her son Jesus, for of no other can they be understood; not of Ahaz’s wife and his son Hezekiah, who was already born, and must be eleven or twelve years of age when these words were spoken; nor of any other son of Ahaz by her or any other person since no other was Lord of Judea; nor of the wife of Isaiah, and any son of his, who never had any that was king of Judah. The prophecy is introduced here as in Isaiah with a “behold!” not only to raise and fix the attention, but to denote that it was something wonderful and extraordinary which was about to be related; and is therefore called twa a…”

“Behold, a virgin--It should be "the virgin" meaning that particular virgin destined to this unparalleled distinction. shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which, being interpreted, is, God with us--Not that He was to have this for a proper name (like "Jesus"), but that He should come to be known in this character, as God manifested in the flesh, and the living bond of holy and most intimate fellowship between God and men from henceforth and for ever.”

“Behold, a virgin shall be with child - Matthew clearly understands this as applying literally to a virgin. Compare Luke 1:34. It thus implies that the conception of Christ was miraculous, or that the body of the Messiah was created directly by the power of God, agreeably to the declaration in Hebrews 10:5; “Wherefore, when he cometh into the world, he saith, Sacrifice and offering thou wouldest not, but a body hast thou prepared me.” And they shall call his name Emmanuel - That is, his name shall be so called. See the notes at Isaiah 7:14. The word “Immanuel” is a Hebrew word, צמנוּאל ‛immânû'êl; cf. Ἐμμανουήλ Emmanouēl, and literally means “God with us.” Matthew doubtless understands…”

“They shall call his name Emmanuel - To be called, only means, according to the Hebrew manner of speaking, that the person spoken of shall really and effectually be what he is called, and actually fulfil that title. Thus, Unto us a child is born - and his name shall be called Wonderful, Counsellor, the Mighty God, the Prince of Peace - That is, he shall be all these, though not so much nominally, as really, and in effect. And thus was he called Emmanuel; which was no common name of Christ, but points out his nature and office; as he is God incarnate, and dwells by his Spirit in the hearts of his people. It is observable, the words in Isaiah are, Thou (namely, his mother) shalt call; but here,…”

“a virgin: Isa 7:14 they shall call his name: or, his name shall be called Emmanuel: Isa 7:14, Isa 8:8, Immanuel God: Mat 28:20; Psa 46:7, Psa 46:11; Isa 8:8-10, Isa 9:6, Isa 9:7, Isa 12:2; Joh 1:14; Act 18:9; Rom 1:3, Rom 1:4, Rom 9:5; Co2 5:19; Ti1 3:16; Ti2 4:17, Ti2 4:22 Matthew 1:24”