(Verse 4) - And being assembled together - Margin, “or, eating together.” This sense is given to this place in the Latin Vulgate, the Ethiopic, and the Syriac versions. But the Greek word has not properly this signification. It has the meaning of “congregating, or assembling.” It should have been, however, translated in the active sense, “and having assembled them together.” The apostles were scattered after his death. But this passage denotes that he had assembled them together by his authority, for the purpose of giving them a charge respecting their conduct when he should have left them. When this occurred does not appear from the narrative; but it is probable that it was not long before his ascension; and it is clear that the place where they were assembled was Jerusalem.

But wait for the promise of the Father - For the fulfillment of the promise respecting the descent of the Holy Spirit made by the Father.

Which ye have heard of me - Which I have made to you. See John 14:16, 26; 15:26; 16:7-13.

(Verse 5) - For John truly baptized  - These are the words of Jesus to his apostles, and he evidently has reference to what was said of John’s baptism compared with his own in Matt. 3:11; John 1:33. In those verses John is represented as baptizing with water, but the Messiah who was to come, as baptizing with the Holy Spirit and with fire. This promise was now about to be fulfilled in a remarkable manner. See Acts 2.

Not many days hence - This was probably spoken not long before his ascension, and of course not many days before the day of Pentecost.