In this verse, the disciples are engaging with Jesus about a theological question that was prevalent among the Jewish people: the return of Elijah before the coming of the Messiah. This expectation is rooted in the prophecy found in Malachi 4:5-6, which states that Elijah will return to prepare the way for the Lord. The teachers of the law, or scribes, emphasized this prophecy, and it was a significant part of Jewish eschatological hope.
The disciples' question reflects their attempt to reconcile this teaching with their understanding of Jesus as the Messiah. Jesus later explains that John the Baptist fulfilled this role, coming in the spirit and power of Elijah to prepare the people for Jesus' ministry. This interaction highlights the importance of understanding prophetic fulfillment in the context of Jesus' life and mission. It also underscores the disciples' journey of learning and growing in their understanding of Jesus' identity and the unfolding of God's plan.