Mat 21:27 Neither shall I tell you by what authority I do these things.

At first glance, it may just look like Christ is being difficult here, frustrating the priest. The truth is that in his short statement, Christ is saying something very important about the nature of knowledge. He is saying that how we perceive our physical reality limits what information we can understand. Remember, Christ parses life into the physical, mental, emotional, and spiritual realms. The physical is what we can see. The mental is what we can hear, that is, what can be spoken and put into symbols. These ideas are all in this series of verse, but they are lost in English because the Greek uses three different words that are all translated as "tell" in them.

Original, Christ asks the priest to tell him the source of John's power using the word epo, which means "to speak" or "to say" (from epos, which means "word'). He also uses the term logos, which means both "word" and "logic" to describe what he does. So Christ is asking about their thinking, that is, their mental realm. He is also referring to his work as mental work (not spiritual), that is, bringing the word and a new way of thinking about things. He gives them two choices: heaven or men, the realm of the spirit or the realm relationships. So, did John's authority come from the spirit or from his place in society?

Responding to his question, the priests said that they cannot "tell," but the word translated as "tell" is eido, which means "to see," "to examine," and "to know." In other words, the priests say that they cannot see where John's authority came from. For Christ, this statement limits their viewpoint to the realm of the physical. Their problem is that they cannot see either spirit or relationships, so they have no opinion on them.

In this response, ending the exchange, the word Christ uses another word for refusing to "tell" them where his authority comes from. It is legô, which means "to gather," "to pick up," "to count," "to tell," "to recount," "to say," "to speak," and "to call by name." It doesn't mean speaking, but in the sense of connecting things together, enumerating things, recounting things.

Christ is saying that our mental world depends on our perceptions of the physical world and how it works. Because the priests cannot look at the physical world and see the role that spirit and relationships plays in it, he cannot explain to them the source of the power of his teaching.

Just so you know, Christ teaches that power of knowledge comes from spirit. It is different from physical power, which comes from social positions and relationships.