The leaders could not deny the healing, so they questioned its source. They asked what power did it and in whose name, meaning by whose authority. Barnes says, "It is very probable that they expected to intimidate the apostles by this question." Gill says they asked whether it was done by a natural, divine, or diabolical power, "whether it was by the use of medicine, or by the help of magic art." The priests and Sadducees were already "grieved" that the apostles were teaching the resurrection through Jesus (Acts 4:2), and this question gave them a way to put that teaching on trial.

"Then Peter, filled with the Holy Ghost" answered plainly: the man stood whole "by the name of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead" (Acts 4:8-10). He called Jesus "the stone which was set at nought of you builders" and declared, "there is none other name under heaven given among men, whereby we must be saved" (Acts 4:11-12). The council "marvelled" at their boldness and "could say nothing against it," since the healed man was standing beside them (Acts 4:13-14).

Barnes identifies "their rulers" as "doubtless the members of the Sanhedrin, or Great Council," the highest Jewish court. Annas and Caiaphas were the same high priests before whom Jesus had been tried (John 18:13, 24). Gill describes the Sanhedrin sitting in a half circle, "as the half of a round corn floor," so that those on trial were set in the middle, which is the picture behind "set them in the midst."

In that world a person's "name" stood for his authority. Barnes reads "by what name" as by whose authority. Peter answered with exactly that word: "by the name of Jesus Christ of Nazareth" (Acts 4:10).

The council asked a hostile question, but it was the right question. Who stands behind this power? God used their cross-examination to give Peter a stage to proclaim the name of Jesus to the very men who had condemned Him. Matthew Henry (Concise) says the miracle "confirmed their testimony to his resurrection from the dead, which proved him to be the Messiah."

The scene also shows how Peter had changed. The same Peter who had said "I am not" His disciple while Jesus stood before Annas and Caiaphas (John 18:24-27) now spoke before those same high priests "filled with the Holy Ghost" (Acts 4:8). The rulers noticed it: "they took knowledge of them, that they had been with Jesus" (Acts 4:13).