In a secret way the Holy Spirit made them understand his words in their language, secretly, without being noticed. These miracles are done by the influence of the Holy Spirit.
For example, the word "home" to someone who knew French would be heard as "la maison". It was a kind of clairvoyance; they heard their own language. The sound was heard in the ear, but inwardly, with the illumination of God, the words were heard in their language.
The Fathers of the Church do not reveal this interpretation of Pentecost very openly, they are afraid of distortion. The same is true of the Apocalypse of John. The ignorant cannot understand the meaning of the mystery of God.
Below he says: "And every soul was filled with fear" (Acts 2:43). This "fear" was not fear. It was something else, something foreign, something incomprehensible, something we cannot explain.
It was awe, it was fulfillment, it was grace. It was being filled with divine grace. At Pentecost, people suddenly found themselves in such a state of deification that they lost it.
Thus, when divine grace overshadowed them, it drove them all crazy - in a good way - it excited them. This has made a big impression on me. It was what I sometimes call a "state of being". It was excitement. A state of spiritual madness.
