But, as appears, many even down to our own time regard Mary, on account of the birth of her child, as having been in the puerperal state, although she was not. For some say that, after she brought forth, she was found, when examined, to be a virgin.
Now such to us are the Scriptures of the Lord, which gave birth to the truth and continue virgin, in the concealment of the mysteries of the truth. “And she brought forth, and yet brought not forth,” says the Scripture; as having conceived of herself, and not from conjunction. Wherefore the Scriptures have conceived to Gnostics; but the heresies, not having learned them, dismissed them as not having conceived.
Clement of Alexandria
The Stromata, Book VII
Chapter XVI