Acts 1:3-5

He also presented himself alive to them, after his Passion, appearing to them throughout forty days and speaking about the kingdom of God with many elucidations. And dining with them, he instructed them that they should not depart from Jerusalem, but that they should wait for the Promise of the Father, "about which you have heard," he said, "from my own mouth. For John, indeed, baptized with water, but you shall be baptized with the Holy Spirit, not many days from now."