Luke 7:20
When the men were come unto him, they said, John Baptist hath sent us unto thee, saying, Art thou he that should come? or look we for another?
Cross-reference
Isaiah 35:5
Prophetic fulfillment
Isaiah 35:5 prophesies the blind seeing and deaf hearing — signs Jesus later cites as proof he is the coming one.
Malachi 3:1
Prophetic fulfillment
Malachi 3:1 predicts the Lord's coming after a messenger — John is that messenger, Jesus is the Lord.
John 11:27
Parallel
John 11:27 has Martha confessing Jesus as the Christ, the one who was to come — directly addressing John's question.