Why was the name of St Joseph not mentioned at Luke 2: 19?

Question

At Luke 2:15-19 (NRSVCE) we see:

When the angels had left them and gone into heaven, the shepherds said to one another, “Let us go now to Bethlehem and see this thing that has taken place, which the Lord has made known to us.” So they went with haste and found Mary and Joseph, and the child lying in the manger. When they saw this, they made known what had been told them about this child; and all who heard it were amazed at what the shepherds told them. But Mary treasured all these words and pondered them in her heart.

My question is: Why was St. Joseph who was also privy to the happenings around Infant Jesus, left out of mention when Luke wrote about St.Mary pondering over the incidents ? What do the Catholic teachings say about that ?

Answer 1

There are a few, related reasons that the Blessed Mother, and not St. Joseph, is said to have "kept all these words, pondering them in her heart" (Lk. 2:19):

On the nativity, Fr. Réginald Garrigou-Lagrange, O.P., writes (Mother of the Saviour and Our Interior Life ch. 3):

Mary grew in humility, poverty and love of God by giving birth to her Son in a stable. His cradle was but a manger. But, by contrast, there were the angels there to sing “Glory to God in the highest; and on earth peace to men of good will.” Those words were sweet to the ears of the shepherds and of St. Joseph, and still more sweet to the ears of Mary. They were the beginning of a Gloria which the Church does not cease to sing at Mass while this world endures, and the liturgy of eternity has not yet replaced that of time.

It is said of Mary that she kept all these words, pondering them in her heart. Though her joy at the birth of her Son was intense, she treasured it up in silence. St. Elisabeth alone received her confidences. God’s greatest actions defy human expression. What could Mary say to equal what she had experienced?

St. Ambrose wrote (quoted in St. Thomas's Catena Aurea on St. Luke's Gospel):

Esteem not the words of the shepherds as mean and despicable: For from the shepherds Mary increases her faith, as it follows: Mary kept all these sayings, and pondered them in her heart. Let us learn the chastity of the sacred Virgin in all things, who no less chaste in her words than in her body, gathered up in her heart the materials of faith.

The third reason Fr. Cornelius à Lapide, S.J., gives in his Commentary on St. Luke, pp. 100-101, is

that in good time she might unfold all these things and narrate them in order to the apostles, and especially to S. Luke, who was destined to write of them. Observe here in the Virgin the rare example of maidenly silence and modesty,* of heavenly prudence, and of the firmest faith and hope, as she wonders at the present and waits for the future.

*cf. 1 Timothy 2:11:

Let the woman learn in silence with all subjection.

Her prompt, unquestioning, silent obedience to St. Joseph telling her they needed to flee to Egypt (Mt. 2:13-14) is another example of her womanly virtues.

Answer 2

I think that, while it's a noble endeavor to know what the back-stories are, those are the stuff of Hollywood movies. To add something here or to comment on why Joseph didn't have a response or why it isn't recorded if he had one, would not be good exegesis.

I could say that it was because Joseph doesn't have major role in any of the Gospels, but Mary's is seen to be by Jesus's side until death and even at the resurrection.

Or, that there are theories that Joseph was actually in his 80's when he married Mary (based on some of the Apocryphal writings) so he most likely died between the story of the boy Jesus in the temple and the start of his ministry. This would mean that Joseph didn't play a big part in the majority of the Gospel writers story leaving one to conclude that he just wasn't that important to include what he thought.

He lived forty years unmarried [from birth]; thereafter his wife remained under his care forty-nine years, and then died. And a year after her death, my mother, the blessed Mary, was entrusted to him by the priests, that he should keep her until the time of her marriage. She spent two years in his house; and in the third year of her stay with Joseph, in the fifteenth year of her age, she brought me forth on earth by a mystery which no creature can penetrate or understand, except myself, and my Father and the Holy Spirit, constituting one essence with myself.
The History of Joseph the Carpenter §14

The whole age of my father, therefore, that righteous old man, was one hundred and eleven years, my Father in heaven having so decreed. The History of Joseph the Carpenter §15

This would mean that if he married Mary at the age of 89 (after Jesus was born) and died at 111, that would mean Jesus would have only been 22 when Joseph died. That is from an apocryphal writing though from the 5th century so is likely not an authority that we can trust but it shows one very early theory and could be possibly true. He would have been alive during the youthful temple visit but not when Jesus started his ministry.

The third was that, since Joseph was not of any blood relation to Jesus, the writers diminished his role other than the fulfillment of the line of David. After that Joseph has no significance.

However, all three of those answers are fully conjecture and cannot be supported by Scripture in any way (outside of the Apocryphal Writings) so it is a question without a real answer.