Acts 1:3-5

For forty days after Jesus had suffered and died, he proved in many ways that he had been raised from death. He appeared to his apostles and spoke to them about God's kingdom. While he was still with them, he said: Don't leave Jerusalem yet. Wait here for the Father to give you the Holy Spirit, just as I told you he has promised to do. John baptized with water, but in a few days you will be baptized with the Holy Spirit.