Malachi 4:6 specifies Elijah's mission of turning hearts—the OT text Jesus directly echoes with 'restore all things'.

Luke 1:16 describes John turning many to God, fulfilling Elijah's restorative role Jesus mentions here.

Luke 1:17 explicitly says John goes in Elijah's spirit and power, directly linking to Jesus' statement about Elijah's coming.

Luke 3:3-14 shows John's baptism of repentance, the preparatory work that fulfills the Elijah role Jesus describes.

Mark 9:11 records the same question about Elijah's coming, directly parallel to Matthew 17:11.

Mark 6:15 records people mistaking Jesus for Elijah, contrasting with Jesus' teaching that Elijah (John) already came.

Mark 15:35 shows bystanders misunderstanding Jesus' cry as calling Elijah, an ironic echo of the earlier discussion.