What happened to Jesus’ disciples can happen to anyone of us if we don’t see the context of what we are either reading or hearing something being explained to us. Jesus was teaching His disciples to be careful of the Pharisees false teachings through their traditions that they added to the Scriptures. Jesus’ followers didn’t pay attention that He was talking about religious leader’s teaching which automatically makes the word leaven to be spiritual and not literal.
Something extraordinary happened when Jesus went up to the mountain with three of His disciples. Two men showed up to Jesus on the mountain from heaven. Moses and Elijah. Moses and Elijah have meanings and so does Jesus. All three were revealing a completion of God’s revelation.