All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them.
Now fifty days after His resurrection, Jesus sends the Holy Spirit as He promised. He will enable them to recall with unerring accuracy everything Jesus taught them during the past three years.
This very day the Spirit will help them share this good news about Jesus and 3,000 people will believe and be baptized.
But first a sign! A sign for the people this message is from God! The apostles begin to speak in foreign languages they never studied.
The timing is perfect. The city of Jerusalem is filled with pilgrims from around the world who have come to celebrate the Passover and have remained for Pentecost.
The sign is perfect for the situation, because of the different dialects in the crowd. How better to show the credibility of these witnesses than to allow them to speak in each of those languages?
Utterly amazed, they asked: “Are not all these men who are speaking Galileans? Then how is it that each of us hears them in his own native language?”
It must have been a most amazing event. These uneducated Galileans speaking in all those different languages at the same time! And it must have been confusing for some also, for in this large crowd some of the languages were naturally unknown to many of the people.
Perhaps this is why some accused the apostles of gibberish – Some… made fun of them and said, "They have had too much wine."
But many heard the apostles speaking their own native language. They understood this would be impossible without Divine Intervention. How else could these witnesses speak in a language they had never studied?
This sign prepares the people to listen with a degree of trustful expectancy to the message they are about to hear.