18Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost.
19Then Joseph her husband, being a just man, and not willing to make her a public example, was minded to put her away privily.
20But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost.
21And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins.
22Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying,
23Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us. Matthew 1/18/23 Holy Bible KJV
And Isaiah said to Ahaz, “Assuredly my Lord will give you a sign of His own accord! Look, the young woman is with child and about to give birth to a son. Let her name him Immanuel. (By the time he learns to reject the bad and choose the good, people will be feeding on curds and honey.) For before the lad knows to reject the bad and choose the good, the ground whose two kings you dread shall be abandoned.” Isaiah 7/14-16 Tanakh
Isaiah writes “So I will wait for the Lord, who is hiding his face from the House of Jacob, and I will trust in him. Here stand I and the children the Lord has given me as signs and portents in Israel from the Lord of Hosts, who dwells on Mount Zion.” Isaiah 8/17-18 Tanakh
Each of Isaiah’s children, “[only] a remnant will turn back”, “with us is God” and “pillage hastens, looting speeds” have a meaning as a sign or portent.
The Book of Isaiah, the Book of 2 Kings and the Book of 2 Chronicles provide the historical account to understand the names of the children the Lord gave Isaiah as signs and portents. The prophetess is foot-noted to be the wife of Isaiah and the young women about to give birth who is with Isaiah, Shear-jashub and Ahaz at the end of the conduit of the Upper Pool, would be his concubine.
The Tanakh does not give an account of the mother of “[only] a remnant will turn back”, as she symbolizes the bride of God, the Jewish People, who is absent until the remnant returns in repentance.
Based on the historical account and the Lord’s signs and portents Isaiah is speaking to Ahaz at the conduit of the Upper Pool no earlier than the eleventh year of his reign, for in his twelfth year (the first year of King Hoshea of Israel) the King of Assyria responded to the request of Ahaz, marched against Damascus, captured it and deported its inhabitants to Kir; and in the ninth year of King Hoshea of Israel, the King of Assyria captured Samaria and deported the Israelites to Assyria.
The hastened and speeded pillaging and looting of Aram and Samaria would have taken place during this deportation.
This means that Immanuel would have been about 9 years old when he came to know right from wrong and that Maher-shalal-hash-baz spoke his first words when the King of Assyria deported Israel.
From the account of signs and portents of the deportation of the northern Kingdom the writer of Matthew says the birth of Jesus by a virgin was prophesied by Isaiah according to the angel of the lord in his dream.
There was no such prophecy. There was a woman with child and that child was named Immanuel as a sign and portent that Judah would not be defeated and deported along with the northern Kingdom.
Would the angel of the Lord tell Joseph in a dream that the prophet (Isaiah) said a virgin would bear a child to be named Jesus when he did not? No.
Would the angel of the Lord tell Joseph in a dream that the Holy Ghost (the spirit of the Holy G-d who is a person) impregnated Mary? No. The spirit of the Holy G-d has no human form and does not have the power to create life. Only G-d can create life.
Why were these things written?
The stories of Jesus including dreams of Joseph and factual accounts are all based on word of mouth from one storyteller to the next long after the death of Jesus and when finally put in writing the strategy and device of giving the oral accounts credibility was to tie the story to the Jewish Bible.
The problem is the Jewish Bible has no such story or prophecy. Trying to make the story fit in the New Testament lead to all the inaccuracies and false statements by the actors, including Jesus, and the theological writings that have evolved trying to explain all these things in Christianity could fill the ocean.