These were the disciples of Jesus Christ earlier on in their teaching, but they just did not get it. They saw things unclearly. They saw God's truth like men as trees walking.
So how could the disciples experience so many of Jesus' miracles and yet be so slow to comprehend who He really was? Sometimes we are slow to understand, and although Christ has led us through trials and temptations before, we are slow to believe. He will do so again and hopefully our hearts are not so closed off that we cannot see clearly all that God can do for us.
Jesus asked His disciples the rhetorical question, "Is your heart still hardened? Are you still resisting the truth of who I am? Are you not clear on My purpose and message?"