What does Acts 12:17 mean?
Peter is finally safe—for now. An angel just rescued him from prison and imminent execution. Days before, Herod Agrippa I arrested and beheaded the apostle James, brother to John and son of Zebedee, then arrested Peter (Acts 12:1–5). Once freed from the prison, Peter came to the home of Mary, mother of John Mark and possibly the host of the first church. A short time of confusion ensued as the Jesus-followers who were praying for his release came to grips with the fact their prayers had been answered (Acts 12:6–16). Now, Peter has a quick opportunity to let them know he is okay before he moves on. To where, we're not told.In many places in the book of Acts, "the brothers" mean other Jesus-followers, including women. Considering Peter lumps them with James, he most likely means the other apostles and church leaders. "James," here, is Jesus' half-brother, the author of the book of James, who apparently leads the church in Jerusalem. Although James rejected the idea his brother was the Messiah before the resurrection (Mark 3:21), he believed after he saw Jesus raised from the dead (1 Corinthians 15:7). He was present in the upper room after the ascension (Acts 1:14) and well-known for his humility and his devotion to Scripture.
This is the last time Peter is mentioned until Acts 15:7 when he speaks in favor of letting the Gentiles remain uncircumcised. After a short interlude to complete Agrippa I's story (Acts 12:20–23), the book of Acts follows the missionary journeys of Paul (Acts 12:25).