Vs.4-5 The apostle along with the disciples were waiting in Jerusalem because they were told to. They were being obedient to the word of God.
The Holy spirit was going to be given to the apostles at that time.  The miraculous gifts of the Holy Spirit were given for; 1. their instruction, 2. to establish the church, 3. As a sign of the New Covenant, 4. As a sign to unbelievers.
These miraculous gifts are not for us today, we have the testimony given by the witnesses. Jesus said "it is and evil and adulterous generation that seeks signs." We will discuss the gift of the Spirit given at baptism another time.
Vs.6 Here we see the disciple were still thinking Jesus was to fulfill an earthly kingdom. They like many others then and now were thinking physical instead of spiritual. Even after many years and much teaching, people still aren't able to see the value of a spiritual life. Fortunately the disciples got the picture and saw the value of what Jesus was doing. The mystery of the spiritual life has been revealed if we can accept it.
Vs.7 Many try to place times on the return of Jesus. This verse tells us we should not be concerned with the times. The only thing Jesus didn't know was the time of the second coming. The disciple would realize shortly that His spiritual kingdom was being built as they spoke. The Jews are still looking for that miraculous physical kingdom. They didn't accept their own messiah because He didn't live up to their unwarranted expectations.
Vs.8 We see these powers given in the first few verses of chapter two. These miraculous powers were not given because Jesus wanted to start a benevolent healing society or a foreign language club. These gifts as I mentioned were for establishing the church. After the church was established, by the apostles, these gifts went away. The apostles were the only ones that could pass them on. After the apostles died there is no proof of miraculous gifts being passed down through the years. Jesus called the apostles witnesses not healers. The miraculous gifts were a witness from God to the people to testify of what Jesus was telling them. Heb. 2:4.

  The apostles were given the task of establishing the church. We have no business trying to establish doctrine or changing things around from what the apostles gave us through the word of God. We don't have to look for more revelations supposedly from God. The book is complete. It says just what God wants us to know. Those who don't believe it try to distort it.
  A further word of proof of the validity of what the Acts says is comparing what other writers say. The apostle Paul writes of several things we see in Acts in his letters to the churches. Peter holds Paul's writings up as  wisdom From God, (II Peter 3:15-16). These cross proofs help us confidently read and understand that what we read is true.
Vs. 9 What an awesome sight that must have been, the Lord being lifted up without any visible means of support, into heaven. This must have been further proof of, 1. Jesus was really in bodily form after being raised from the dead. 2. Jesus was not attempting to establish an earthly kingdom. 3. He was going as He said He would, to the Father. 4. They were left to establish His church by His authority with the help of the Holy Spirit.
Vs.10-11 Their disappointment to see their leader and teacher disappear from their sight must have