Luke 9:7 reports Herod's speculation that Jesus is John raised — directly echoed in the disciples' answer here.

Luke 9:8 lists popular opinions — Elijah or a prophet — which the disciples repeat verbatim in this verse.

In Luke 9:30, Moses and Elijah appear with Jesus, directly connecting to the speculation here that Jesus is Elijah or a prophet.

Malachi 4:5 prophesies God sending Elijah before the great day — the source of the speculation that Jesus might be Elijah.

Matthew 14:2 shows Herod believing Jesus is John the Baptist risen — a parallel instance of the same identification.

Mark 6:15 records the same rumors about Jesus being Elijah or a prophet — a parallel account of public opinion.

John 1:25 lists the same three expected figures (Christ, Elijah, the Prophet) that people considered for Jesus in Luke 9:19.

Matthew 16:14 is the parallel account of the same event, adding 'or Jeremiah' to the list of speculations.

John 1:21 has John the Baptist denying he is Elijah, revealing the public expectation that Elijah must come — background to the speculation about Jesus.

Mark 8:27 records Jesus asking the same question that led to the answer in Luke 9:19 — the shared narrative context.

John 7:40 has people declaring Jesus is the Prophet — another example of the identification mentioned in Luke 9:19.

John 9:17 shows the healed blind man calling Jesus a prophet — a personal confession matching the public speculation.