Acts 1:1-8 NKJV
The former account I made, O Theophilus, of all that Jesus began both to do and teach, until the day in which He was taken up, after He through the Holy Spirit had given commandments to the apostles whom He had chosen, to whom He also presented Himself alive after His suffering by many infallible proofs, being seen by them during forty days and speaking of the things pertaining to the kingdom of God.
And being assembled together with them, He commanded them not to depart from Jerusalem, but to wait for the Promise of the Father, “which,” He said, “you have heard from Me; for John truly baptized with water, but you shall be baptized with the Holy Spirit not many days from now.” Therefore, when they had come together, they asked Him, saying, “Lord, will You at this time restore the kingdom to Israel?” And He said to them, “It is not for you to know times or seasons which the Father has put in His own authority. But you shall receive power when the Holy Spirit has come upon you; and you shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth.”
NKJV: New King James Version