Where does the Catholic tradition that Mary did not have pain giving birth to Jesus come from?

Question

Where does the Catholic tradition that Mary's birth of Jesus was painless come from?

My wife just got home from a non-denominational study about Mary and she said she thought everybody knew this, but apparently no one knew about it - especially the Protestants!

In any event, what I'm looking for is the origin of the quote that Jesus' birth was "like light passing through glass" and whether that quote is wholly indicative of a painless birth or if it could have been painless in another way?

I understand that it's a little t tradition in the Church, not a dogma or anything. But it's definitely a strong tradition; although it's one that could use a little preaching on from what I can tell.

Answer 1

The Catholic "tradition" is just that. It is not an official teaching or doctrine, but rather something one is free to believe. The Church does not take a physiological stance on whether or not Mary experienced pain during child birth. But to understand where this tradition came from, we have to go back to the Garden of Eden.

When Adam and Eve sinned, God said to Eve that because of her sin, women would now experience pain during child birth. The teaching of "Original Sin" is that we have all inherited the sin of Adam and Eve. 

The Catholic Church teaches that Mary was "the ark of the new covenant" and that God prepared her to be the perfect vessel which carried God (Jesus) into the world. That meant that she needed to be free from Original Sin and that she did not commit a sin.

So since she was free from sin, including the sin from Eve, the tradition is that she did not need to experience pain during child birth.

You can read more about the teaching on "the ark of the new covenant" here: https://www.catholic.com/magazine/print-edition/mary-the-ark-of-the-new-covenant

Answer 2

Extensive biblical and traditional material advocating for Mary's painless childbirth can be found from "The Virginity of Our Lady in Partu". Many Protestants reject this teaching, but most are unaware of it entirely. I don't know the status of this teaching among Protestant theologians.

The image of light passing through glass seems to originate in the 12th century, and becomes very widespread by the 14th century. See this scholarly overview of the sources:
Breeze, Andrew. "The blessed virgin and the sunbeam through glass." Bells: Barcelona English language and literature studies 2 (1990): 53-64.

The teaching continued to be promulgated through the Catechism of the Council of Trent:

"He is born of His Mother without any diminution of her maternal virginity, just as He afterwards went forth from the sepulchre while it was closed and sealed, and entered the room in which His disciples were assembled, the doors being shut; or, not to depart from every-day examples, just as the rays of the sun penetrate without breaking or injuring in the least the solid substance of glass, so after a like but more exalted manner did Jesus Christ come forth from His mother's womb without injury to her maternal virginity."

"Catechism of the Council of Trent" 1566, Part I: The Creed, Article III

You also wanted to know about interpretations of this tradition. Some of the traditional sources use the image to refer to Christ's conception, not birth (Breeze). The primary concerns of traditional authors are

1. Mary's perpetual virginity
2. Reversal of the curse of Adam and Eve.
3. That Christ's birth should not cause distress

Answer 3

Her painless childbirth follows from these truths of divine revelation:

1. Painful childbirth is one of the punishments of Original Sin (Gen. 3:16: "in travail shalt thou bring forth children").
2. Mary did not have Original Sin (dogma of the Immaculate Conception).

Therefore,

3. Mary did not have a painful childbirth (at least not as a result of Original Sin).

St. Thomas Aquinas, answering the question "Whether Christ was born without His Mother suffering?" (Summa Theologica q. 35 a. 6), writes:

The pains of childbirth are caused by the infant opening the passage from the womb. Now it has been said above (q. 12 a. 2, Replies to objections), that Christ came forth from the closed womb of His Mother, and, consequently, without opening the passage. Consequently there was no pain in that birth, as neither was there any corruption; on the contrary, there was much joy therein for that God-Man "was born into the world," according to Is. 35:1,2: "Like the lily, it shall bud forth and blossom, and shall rejoice with joy and praise."

Also, Song 4:12 is cited as evidence her parturition must have been miraculous:

My sister, my spouse, is a garden enclosed, a fountain sealed up.

and Ezechiel 42:2:

This gate shall be shut, it shall not be opened, and no man shall pass through it: because the Lord the God of Israel hath entered in by it, and it shall be shut

Answer 4

It is in prophecy of Isiah regarding the birth of the Messiah.

"Before she travailed, she brought forth; before her pain came, she was delivered of a man child” (Isa 66:7)

Answer 5

The idea of "no pain in birth" sources generally to the Infancy Gospel of James. And to those like Marcion, Valentinus, Apelles, and others who taught various ideas about Jesus' flesh. These were the docetists.

Here's the Infancy Gospel of James.

[19]Then said Salome: As the Lord my God liveth, unless I thrust in my finger, and search the parts, I will not believe that a virgin has brought forth. 20. And the midwife went in, and said to Mary: Show thyself; for no small controversy has arisen about thee. And Salome put in her finger, and cried out, and said: Woe is me for mine iniquity and mine unbelief, because I have tempted the living God; and, behold, my hand is dropping off as if burned with fire. Infancy Gospel of James

Prior to this, a bright light had appeared in the cave. It receded and the infant appears at Mary's side. This "virginal birth" gave rise to the subsequent belief that Jesus was born from the east gate, not the south gate (Eze 44:1-2).

The idea relating this birth to light passing through glass or water through a tube sources to Valentinus, et al.

Some, however, make the assertion, that this dispensational Jesus did become incarnate, and suffered, whom they represent as having passed through Mary just as water through a tube; enter link description here

So, the idea of a painless birth arose apart from scripture in denying the natural flesh of Christ. Centuries later the idea of a miraculous painless birth became "orthodox".