Acts 1:3-5

3 To whom also he presented himself alive after his passion, by many infallible proofs, being seen by them forty days, and speaking of the things pertaining to the kingdom of God.

4 And having assembled them together, he commanded them, not to depart from Jerusalem, but to wait for the promise of the Father, which, saith he, ye have heard from me.

5 For John indeed baptized with water; but ye shall be baptized with the Holy Ghost, not many days hence.