2 until the day when he was taken up, after he had given commandment through the Holy Spirit to the apostles whom he had chosen. 3 To them he presented himself alive after his passion by many proofs, appearing to them during forty days, and speaking of the kingdom of God. 4 And while staying with them he charged them not to depart from Jerusalem, but to wait for the promise of the Father, which, he said, "you heard from me,
Matthew Henry's Commentary on Acts 1:2-4
Commentary on Acts 1:1-5
(Read Acts 1:1-5)
Our Lord told the disciples the work they were to do. The apostles met together at Jerusalem; Christ having ordered them not to depart thence, but to wait for the pouring out of the Holy Spirit. This would be a baptism by the Holy Ghost, giving them power to work miracles, and enlightening and sanctifying their souls. This confirms the Divine promise, and encourages us to depend upon it, that we have heard it from Christ; for in Him all the promises of God are yea and amen.