Matthew 11:14 explicitly states John is Elijah, clarifying the disciples' understanding here.

Matthew 3:1 introduces John the Baptist, whom Jesus identifies as Elijah in Matthew 17:13 – a direct link to the Elijah prophecy.

Matthew 11:9 records Jesus affirming John as more than a prophet and as Elijah, reinforcing the identification made in Matthew 17:13.

Mark 9:13 is the synoptic parallel to Matthew 17:13, stating Elijah has come and they did to him as written.