In other words. No proof at all.
Pretty much the way I read it too. He offers nothing to the conversation. I'm a Christian and need no further proof than God's word and what I know to the depths of my being. My God is real.
Prove to the deaf that there is a sense of hearing; sight to the blind.
Faith is the greatest of all, and you only have to initiate contact with a desire to truly know. If you are truthful in your heart about that desire, He will answer the knock on His door.
What happens after is remarkable.