And he saith to them: If I shall tell you, you will not believe me.

"Are you the Christ? Tell us." "If I tell you," He replied, "you will certainly not believe;

If you are the Christ, say so. But he said, If I say so you will not have belief;

If you are the Messiah, tell us. But he said to them, 'If I tell you, you won't believe,

"If you are the Christ," they said, "tell us so." "If I tell you," replied Jesus, "you will not believe me;

Saying, art thou the Christ,.... The Messiah, promised and prophesied of by Moses, and all the prophets, and long expected by us: "tell us". The Ethiopic version adds, openly; tell us frankly, freely, plainly, as in John 10:24.
And he said unto them, if I tell you, you will not believe. The Vulgate Latin and Syriac versions read, "will not believe me"; neither what he said, nor that he was the Messiah; they were determined not to believe in him, and receive him as such; their unbelief was wilful, obstinate, and invincible: they were proof against all arguments, evidence, and demonstration itself.

Art thou the Christ? He had already answered in the night and been condemned (Matthew 26:63-64). His reply here is a protest.