Acts 1:3-5

unto whom he also showed himself alive, after he had suffered, by many infallible proofs, appearing unto them for forty days and speaking to them of the kingdom of God; and gathering them together, he commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, Which, he said, ye have heard of me. For John truly baptized in water, but ye shall be baptized in the Holy Spirit not many days from now.