A frequent misinterpretation claims that 'till' definitively proves Joseph and Mary had sexual relations and other children after Jesus' birth, undermining doctrines of Mary's perpetual virginity; however, the Greek word for 'till' (heos) and its English equivalent do not necessitate a change in circumstance afterward, as evidenced by parallel uses in passages like 2 Samuel 6:23 or Matthew 28:20, where no subsequent action is implied, with the verse's intent focused narrowly on affirming the virgin conception up to Jesus' birth rather than prescribing future marital intimacy.
Matthew 1:25
King James Version (1769)
25 And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
This verse underscores Joseph's restraint from sexual relations with Mary until after she gave birth to her firstborn son Jesus, safeguarding the miracle of the virgin birth prophesied in Isaiah 7:14, while demonstrating his obedient faith in naming the child Jesus as commanded by the angel, thereby integrating Jesus into the Davidic lineage as the promised Messiah.