What does “To know” & “Until” mean? by Jerome

“On this point especially, my adversary works up a sweat, laboring to no purpose, striving to make the term “to know” (cognoscere) refer to sexual relations rather than to knowledge, as if anyone had ever denied this fact and as if any intelligent person could ever have imagined any assertions as stupid as those he refutes.
Then he means to prove that the adverb “until” (done or usque) designates a limited period of time and that, when said time is concluded, there occurs an event that, up until that point in time, had not yet taken place, as in the following passage: “And he did not know her until she gave birth to a Son.” It is obvious, he says, that he knew her after she gave birth and that the birth of the child simply delayed sexual relations.
To prove this point, he gathers together many examples from the Scriptures and brandishes his sword in the dark, like the blindfolded gladiators, making his tongue vibrate with his own noise, wounding no one but the members of his own body.”

Jerome, De perpetua virginitate, s; PL 23, 198.