Verse 3: Matthew (like the other three synoptic Gospel writers) quotes from Isaiah 40:3 to describe John’s mission. (Matthew quotes from the Greek version rather than the Hebrew, which explains why there are differences between what he says and our version of Isaiah 40:3.) How does that verse from Isaiah explain John’s mission? Does it shed any light on what John means when he warns that the kingdom of heaven is at hand?
Verse 4: This verse reminds us of Elijah. (See 2 Kings 1:8; see also Matthew 11:14 and 17:10-12.) Why is that parallel important? Does Zechariah 13:4 teach us anything about John the Baptist?