By Fr. David Howell, Catholic Herald - The angel freed Peter from Herod’s prison by miraculously unlocking several doors, as if the keys of the kingdom which Jesus had given him were at work in a concrete way... These metaphorical keys allude to Isaiah 22:22, where the king invests his prime minister with his own authority through the symbol of a key. Jesus himself, in Revelation, states that the key is his (3:7), but it is lent to Peter and his successors until the last day, when Jesus will receive it back—as depicted in Michelangelo’s Last Judgement. The papacy is the gift of Christ’s own authority, given to us to open heaven.