Direct biblical statement
Matthew 1:24–25
Joseph receives Mary
24 And Joseph rising up from sleep, did as the angel of the Lord had commanded him, and took unto him his wife.
25 And he knew her not till she brought forth her first born son: and he called his name Jesus.
Douay–Rheims · Challoner revision · Matthew 1:24–25
Why this matters
Joseph obeys the angel and names the child Jesus. The passage affirms the virginal conception; the word “till” does not, by itself, settle later questions about perpetual virginity. Christian traditions differ in reading the wider evidence.