Matthew Poole and continuators on Acts 19:3

3 And he said unto them, Unto what then were ye baptized? And they said, Unto Johns baptism.

What Doctrine did you make profession of? And what Religion did you Seal unto at your Baptism?

The Doctrine that Iohn taught, and the Religion that he professed and preached. Thus the Iews are said, 1 Cor. 10.2. to be Baptized unto Moses, being engaged to believe the Doctrine, and observe the Law delivered by Moses. Now the Baptist, as Chap. 18.25. preached indeed Christ, but many things concerning him he could not preach, unless as of things to come: as his Death, and Resurrection. The Baptist being Beheaded before our Saviours Death, and the Holy Ghost was not poured out in that extraordinary manner, until after our Saviours Resurrection and Ascension; which pouring out of the Spirit, these Disciples at Ephesus, having been Baptized by Iohn in Iudea, and afterwards returning home, might not have heard of.