The first example of the gift of tongues in the New Testament occurred on the Day of Pentecost.
- And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit was giving them utterance. […] They were amazed and astonished, saying, Why, are not all these who are speaking Galileans? And how is it that we each hear them in our own language to which we were born? - Acts 2:4, 7-8
Acts 2:4 states that the disciples were speaking with other tongues (heteros glōssa) or different languages. As the crowd heard the Apostles speaking, everyone heard in their own language.
There are only two other examples of the gift of tongues being displayed in the book of Acts — Acts 10 and 19. In both incidents the gift was displayed by new believers as a sign that the Gospel had spread beyond Judea. Paul confirmed that the gift of tongues was given as a sign to unbelieving Jews.
- So then tongues are for a sign, not to those who believe but to unbelievers; - 1 Corinthians 14:22
When Paul writes to the Corinthians on the topic of spiritual gifts, he refers to tongues as a lesser gift.
- And God has appointed in the church, first apostles, second prophets, third teachers, then miracles, then gifts of healings, helps, administrations, various kinds of tongues. - 1 Corinthians 12:28
That tongues is mentioned last implies that the gift was neither foundational nor primary.
Along with the gift of tongues is the gift of the interpretation of tongues. The gift refers to the supernatural ability to translate what was spoken in tongues by those who did not speak the language. Paul told the Corinthians church that if someone spoke in tongues there must be an interpreter present who can translate for the others in the assembly. If there is no interpreter, the one with the gift of tongues is to remain silent in the church.
- If anyone speaks in a tongue, it should be by two or at the most three, and each in turn, and one must interpret; but if there is no interpreter, he must keep silent in the church; and let him speak to himself and to God. - 1 Corinthians 14:27-28