The first reading at Mass today recalls the event as described in Acts of the Apostles Chapter 2:
When the time for Pentecost was fulfilled,
they were all in one place together.
And suddenly there came from the sky
a noise like a strong driving wind,
and it filled the entire house in which they were.
Then there appeared to them tongues as of fire,
which parted and came to rest on each one of them.
And they were all filled with the Holy Spirit
and began to speak in different tongues,
as the Spirit enabled them to proclaim.
Now there were devout Jews from every nation under heaven
staying in Jerusalem.
At this sound, they gathered in a large crowd,
but they were confused
because each one heard them speaking in his own language.
They were astounded, and in amazement they asked,
“Are not all these people who are speaking Galileans?
Then how does each of us hear them in his native language?
We are Parthians, Medes, and Elamites,
inhabitants of Mesopotamia, Judea and Cappadocia,
Pontus and Asia, Phrygia and Pamphylia,
Egypt and the districts of Libya near Cyrene,
as well as travelers from Rome,
both Jews and converts to Judaism, Cretans and Arabs,
yet we hear them speaking in our own tongues
of the mighty acts of God.”