John Calvin on John 18:18

18. And Simon Peter was standing with them. When the evangelist adds that Peter was standing near the fire, along with the others and servants, this serves to connect the various parts of the narrative, as we shall afterwards see. But this shows how great was Peter’s stupidity, when, without the least concern, he warmed himself along with a multitude of wicked men, after having denied his Master; though it is possible that he may have been restrained by fear lest, in going out of the high priest’s house, he should fall into another danger of the same kind.

John 18:19-24

19. The high priest then asked Jesus concerning his disciples, and concerning his doctrine. 20. Jesus answered him, I spoke openly in the world; I always taught in the synagogue and in the temple, where all the Jews assemble, and in secret I have spoken nothing. 21. Why askest thou me? Ask those who have heard what I have spoken to them: behold, they know what I have said. 22. When he had said these things, one of the officers that stood by struck Jesus with the palm of his hand, saying, Answerest thou the high priest so? 23. Jesus answered him, If I have spoken evil, bear witness of the evil; but if well, why smitest thou me? 24. Now Annas had sent him bound to Calaphas the high priest.