And he knew her not till she brought forth her firstborn son:
and he called his name Jesus.
Matthew 1, 25

Many Protestants who reject the Catholic dogma of the Perpetual Virginity of Mary believe that Mary and Joseph had conjugal relations and children after the birth of Jesus. To support their belief, they often cite Matthew 1:25 as a proof-text. However, this interpretation relies on a modern English use of the preposition "until," which may not accurately reflect the original meaning of the text. To fully understand what Matthew is saying in this passage, we must examine the Hebrew and Greek meanings of this word. It is important to note that Matthew was a Jewish Christian who wrote his gospel for a Hebrew audience, and the text was originally written in Hebrew and later translated into Koine Greek.

It is unfortunate that the original meanings of words and phrases in the Bible are often lost in subsequent translations. Therefore, it is important for us to examine the original form and context of the word ourselves to understand what the sacred author intended to convey. Let's temporarily forget how the word "until" is commonly used in modern English and look at the passage with a fresh perspective.

The words 'until' and 'till' in Semitic and Greek languages (such as 'ad' and 'heos') are used to indicate the time period leading up to an event, without implying anything that might happen after it. The importance lies solely in what occurs before the event. To understand how this grammatical concept works and what it means, let's explore a few passages from the Hebrew Old Testament, as translated into English in the King James Bible.

לְדָוִ֗ד מִ֫זְמֹ֥ור נְאֻ֤ם יְהוָ֨ה ׀ לַֽאדֹנִ֗י שֵׁ֥ב לִֽימִינִ֑י עַד־אָשִׁ֥ית אֹ֝יְבֶ֗יךָ הֲדֹ֣ם לְרַגְלֶֽיךָ׃

A Psalm of David. The LORD said unto my Lord, Sit thou at my right hand,
until I make thine enemies thy footstool.
– Psalm 110, 1

The preposition 'aḏ (עַד)' literally means "up to the time of". This Messianic prophecy refers to the period when Jesus will sit at the right hand of God until his enemies are made his footstool. The author does not imply that Jesus will cease to sit at the right hand of God after his enemies are defeated. Similarly, in the Gospel of Matthew, the author does not mean to suggest that Joseph had conjugal relations with Mary after the birth of Jesus. Matthew simply meant to convey that the couple did not have any marital relations up to the time of Jesus' birth. Let's look at another example from the Old Testament.

לְמִיכַל֙ בַּת־שָׁא֔וּל לֹֽא־הָ֥יָה לָ֖הּ יָ֑לֶד עַ֖ד יֹ֥ום מֹותָֽהּ׃ פ

Therefore, Michal the daughter of Saul had no child unto the day of her death.
– 2 Samuel 6, 23

The Semitic locution 'ad' is present in this context. However, the translation to English is less confusing if we use the word 'unto' instead of 'until.' The Hebrew text of this verse literally means 'up to,' 'to,' or 'until' (the day of). Obviously, Michal could not have had any children after her death, but that is not the point. What matters is the intended meaning of the author, which is that Michal remained childless until the day of her death, without any irrelevant or nonsensical implications.

Matthew's intention in his gospel was to emphasize the truth of the Incarnation, which was difficult for many Jews to accept. He does not need to imply that Joseph and Mary did not have conjugal relations until after the birth of Jesus to convey this message. All he needs to state is that they did not have any marital relations "before" or "up until" the birth of Jesus. By doing so, he is underscoring the fact that Mary conceived Jesus by the supernatural power of the Holy Spirit. This implication is contained in the statement, and it is relevant to what Matthew is proposing in contrast to traditional Judaic beliefs.

In the Gospel of Matthew, the original Greek translation uses the word "heos" or ἕως for the term "until". This word refers to the time leading up to an event and means "up to the time of" or "hitherto" without implying anything unrelated that might come after. Matthew is primarily concerned with how Mary and Joseph related to each other before the conception and birth of Jesus. This is evident when the author quotes Isaiah 7:14 in verses 22-23. The main point is that Jesus is the long-awaited Messiah of the Hebrew people, but he isn't of paternal human lineage as the Jews expect. If the evangelist intended to convey that Joseph did not know his wife "until after" the birth of Jesus, the Greek phrase would have been "έως ότου" instead. In simple terms, the Greek word for "until" does not mean or imply "until after," but rather "up until."

Nevertheless, some Protestants adamantly maintain that because the original Greek text reads heos hou (ἕως οὗ), it follows a reference to the time after the birth of Jesus can be made. The phrase heos hou (up to the time of – that) somehow lends them the notion that Joseph did not have sexual relations with his wife Mary until “after” she had brought forth her firstborn son. The Greek text literally reads: “And (he) knew her not until that (time when) she had brought forth a son.” However, the demonstrative “that” is being used to emphasize the couple had no conjugal relations up until that time when Mary had brought forth Jesus. In other words, she did not conceive her son by her husband’s seed. The use of the negative form – “knew her not until” – makes no difference, at least not in Koine Greek, unlike modern English. It simply means the couple had no marital relations up to the time Jesus was born, and so Joseph isn’t his natural father.

Anyway, many Protestants continue to argue that Mary's virginity ended after the birth of Jesus, based on the grammatical structure of the phrase "heos hou" used in the verse. However, "heos hou" can be used interchangeably with "heos" and mean "up to the time of". Another example of this usage can be found in the New Testament in Acts 25:21, where it says, "But when Paul had appealed to be kept in custody for the decision of the emperor, I commanded him to be held until (heos hou) I could send him to Caesar". We know that the apostle remained in custody after he was sent to Caesar. Therefore, the action of the main clause (the command to be held in custody) did not necessarily cease upon the pivotal event (being sent to Caesar) in the linear course of time. In the same way, Mary's virginity did not necessarily end after the birth of Christ, just as Paul was not free from his chains at any point after being sent to Caesar.

Still, one could easily have the impression that Matthew implies Joseph and Mary had marital relations after Jesus was born when he reads the text in modern English and even with preconceived notions. However, the word “until” does not refer to the future in ancient Greek and Hebrew, and sometimes it might not even be used in modern English, depending on the speaker’s intention. For instance: “After the teacher had left the classroom, the students did not make any noise until he returned.” The speaker could mean, in all probability, that the students worked quietly after the teacher left the classroom and continued to work quietly before he returned. He doesn’t necessarily have to mean that the students became noisy after the teacher returned.

Matthew's statement "Joseph did not know Mary – he knew her not – until (heos hou) the birth of her firstborn son" does not necessarily mean that Mary and Joseph had no conjugal relations until after Jesus was born. Instead, it may imply that they never had sexual relations before Jesus was conceived to emphasise the divinity of the Messiah. It is worth noting that the couple celebrated their second and final marriage ceremony (Nisuin) at the time Jesus was born, and he was regarded as "the carpenter's son" (Mt 13:55).

It's important to note that many Protestants fail to consider an important factor in the equation. In the verse, the word "know" is written in the imperfect tense (eginosken) instead of the aorist (egnosken). This difference in tense emphasizes the duration of time during which Mary and Joseph refrained from having sexual relations. Essentially, the couple abstained from intercourse leading up to the birth of Jesus. This interpretation aligns with the verse's context, which describes the virgin birth of Jesus and its implications for his natural paternity. If Matthew wanted to indicate that Mary and Joseph had consummated their marriage, as most couples do, he would have used the aorist tense in the Greek translation.

The aorist tense of a verb denotes an action that occurred in the past without any reference to its duration or completion. Therefore, the future is not discounted. It is possible that Mary and Joseph had conjugal relations after the birth of Jesus, but Matthew's intention was not to tell us about that. Instead, his intention was to emphasize that the couple did not have conjugal relations before Jesus was born. He does this to reinforce what he writes in the preceding verses (1:22-23), "Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying, 'Behold, 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."

“And when he had taken her, he knew her not, till she had brought forth her first
born Son.’ He hath here used the word till,’ not that thou shouldest suspect
that afterwards he did know her, but to inform thee that before the birth the
Virgin was wholly untouched by man. But why then, it may be said, hath he used
the word, till’? Because it is usual in Scripture often to do this, and to use this
expression without reference to limited times. For so with respect to the ark
likewise, it is said, The raven returned not till the earth was dried up.’ And yet it
did not return even after that time. And when discoursing also of God, the
Scripture saith, From age until age Thou art,’ not as fixing limits in this case.
And again, when it is preaching the Gospel beforehand, and saying, In his days
shall righteousness flourish, and abundance of peace, till the moon be taken
away,’ it doth not set a limit to this fair part of creation. So then here likewise, it
uses the word “till,” to make certain what was before the birth, but as to what
follows, it leaves thee to make the inference.”
St. John Chrysostom, Gospel of Matthew, V:5
(AD 370)

And Mary said to the angel: How shall this be done,
because I know not man?
Luke 1, 34

https://www.hailholyqueen.net/the-perpetual-virginity/i-know-not-man