Acts 1:5 - Ellicott's Commentary On The Whole Bible

John truly baptized with water. — See Note on Matthew 3:11. The words threw the disciples back upon their recollection of their first admission to the Kingdom. Some of them, at least, must have remembered also the teaching which had told them of the new birth of water and of the Spirit (John 3:3-5). Now they were told that their spirits were to be as fully baptised, i.e., plunged, into the power of the Divine Spirit, as their bodies had then been plunged in the waters of the Jordan. And this was to be “not many days hence.” The time was left undefined, as a discipline to their faith and patience. They were told that it would not be long, lest faith and patience should fail.