The keys of the house

In those days a key was a sign of authority. In the book of Isaiah, Eliakim, the steward of the palace, is given the key of the house of David, laid on his shoulder. What he opens, no one shuts, and what he shuts, no one opens. A steward decided who came in.

In Jewish teaching, binding and loosing meant forbidding and permitting. So Peter is given responsibility in God's house: he may show people the way in. At Pentecost, when he spoke about Jesus to a large crowd in Jerusalem, he did exactly that. For thousands of people the door to faith opened that day.