Acts 4:31

It is not clear whether we should understand the shaking of the place where the disciples had assembled literally or metaphorically (cf. Exodus 19:18; 1 Kings 19:11-12; Isaiah 6:4; Acts 16:26). In either case those assembled received assurance from this phenomenon that God was among them and would grant their petition.

"This was one of the signs which indicated a theophany in the Old Testament (Exodus 19:18; Isaiah 6:4), and it would have been regarded as indicating a divine response to prayer." [Note: Marshall, The Acts . . ., p. 107.]

The same control by the Spirit that had characterized Peter (Acts 4:8) and the disciples earlier (Acts 2:4) also marked these Christians. They now spoke boldly (Gr. parresias, with confidence, forthrightly; cf. Acts 4:13; Acts 4:29) as witnesses, as Peter had done. Note that tongues speaking did not occur here. This was not another baptism with the Spirit but simply a fresh filling.

"In Luke 22:39-46, just before Jesus’ arrest and just after Peter’s assertion of readiness to suffer, Jesus urged the disciples to pray in order that they might not enter into temptation. Instead, the disciples fell asleep and were unprepared for the following crisis. In Acts 4:23-31 Jesus’ followers are again confronted with the dangerous opposition of the Sanhedrin. Now they pray as they had previously been told to do. As a result they receive power from God to continue the mission despite the opposition. We have already noted that Peter’s boldness before the Sanhedrin in Acts contrasts with his denial of Jesus in Luke. The church in Acts, finding power for witness in prayer, also contrasts with the disciples who slept instead of praying in Luke. These contrasts contribute to the narrator’s picture of a dramatic transformation in Jesus’ followers." [Note: Tannehill, 2:71-72.]