Final answer:
Peter referenced the prophet Joel as the one who prophesied the events of the Day of Pentecost, as described in the Book of Acts.
Step-by-step explanation:
On the Day of Pentecost, the Apostle Peter referenced the prophet Joel as prophesying the events that unfolded. Peter quotes from the Book of Joel in Acts 2:16-21, explaining that the coming of the Holy Spirit and the speaking in tongues fulfilled what Joel had foreshadowed. According to Peter, Joel foretold that God would pour out His Spirit upon all people, and this would be accompanied by various signs and wonders.