“We know” = Ironically, the Pharisees say this phrase many times. It is indeed an indication of their real problem — pride. They think they know the answers and are therefore not open to receiving the truth when it comes in a form they don’t recognize.

“Give glory to God” = has 2 possible meanings neither of which is to thank God for what He has done through Jesus:

1. An exhortation to speak the truth. The thought is that God sees everything and knows everything, so why try to hide anything; give Him the honor He is due by telling the truth. (Joshua 7:19) The Jews are telling the man they know he has not told the whole truth as yet.
   Joshua 7:19  Then Joshua said to Achan, “My son, give glory to the LORD, the God of Israel, and give him the praise. Tell me what you have done; do not hide it from me.”
2. Give the glory for this miracle to God and not to Jesus. The thought would be that Jesus is a sinner and could not have had anything to do with this miracle.

Either way, the man is told that they have determined Jesus to be a sinner and could not have had anything to do with the miracle, so the man must recant his story. He must accept their ecclesiastical authority and submit to their determination that Jesus is a sinner. They have used their own logic based upon false presumptions and are now wielding their authority as a bludgeon to force their will. Of course, Jesus was not a sinner, but He did come in the form of one.

Romans 8:3  For what the law was powerless to do in that it was weakened by the sinful nature, God did by sending his own Son in the likeness of sinful man to be a sin offering. And so he condemned sin in sinful man,