John Calvin Commentary Acts 21:9

"Now this man had four virgin daughters, who prophesied." — Acts 21:9 (ASV)

Four daughters. This is added for the commendation of Philip, not only that we might know that his house was well ordered, but also that it was famous and excellent through the blessing of God. For, certainly, it was no small gift to have four daughters all endowed with the spirit of prophecy.

In this way, the Lord intended to beautify the first beginnings of the gospel when He raised up men and women to foretell things to come. Prophecies had by then almost ceased for many years among the Jews, so that they might be more attentive and eager to hear the new voice of the gospel.

Therefore, seeing that prophesying, which had in a way almost ceased, was now returning after a long time, it was a sign of a more perfect state. Nevertheless, it seems that this was the reason why it ceased shortly afterward; for God supported His people of old with various foretellings until Christ would bring an end to all prophecies.

Therefore, it was fitting that the new kingdom of Christ should be thus equipped and beautified with this gift, so that everyone might know that the promised visitation of the Lord was present. It was also expedient that it should last only for a short time, lest the faithful should always be waiting for something further, or lest inquisitive minds might be given an opportunity to seek or invent some new thing from time to time.

For we know that when that ability and skill were taken away, there were, nevertheless, many deluded individuals who boasted that they were prophets. It may also be that the waywardness of people deprived the Church of this gift. But that one reason should be sufficient: that God, by taking away prophecies, testified that the end and perfection was present in Christ.

It is uncertain how these young women carried out their prophetic role, except that the Spirit of God so guided and governed them that He did not overturn the order which He Himself had established. And inasmuch as He does not permit women to bear any public office in the Church, it is to be supposed that they prophesied at home, or in some private place, outside the public assembly.