John 18:28

They led Jesus therefore from Caiaphas into the Praetorium: and it was early; and they themselves entered not into the Praetorium, that they might not be defiled, but might eat the passover.

This and John 18:24 are John's only reference to the formal trial in the Sanhedrin. He also omitted the all-night examination before Caiaphas, and the trial before Herod. Of the six trials before: (1) Annas, (2) Caiaphas, (3) the Sanhedrin, (4) Pilate, (5) Herod, and (6) Pilate; John mentioned (1), (4) and (6).

That they might not be defiled ... What a perverse inconsistency marks the behavior of men! They were willing to suborn testimony to effect the judicial murder of the Son of God, but were unwilling to put foot in a Gentile's house on the day of the Preparation. This is the classical demonstration of the manner in which the strictest observance of religious ceremonies can exist in the behavior of wicked men at the very time when they are engaged in the blackest criminal activity. Pilate, who was certainly inconvenienced by having to go down at such an early hour and outside his palace to keep from defiling THEM (!), must surely have resented the necessity of participating in such an affair.

That they might eat the passover ... In the light of this, there is no way to make the last supper of the previous evening to have been the Passover.