Jamieson, Fausset and Brown on Mark 14:68

68. But he denied--"before all" (Mt 26:70).

saying, I know not, neither understand I what thou sayest--in Luke (Lu 22:57), "I know Him not."

And he went out into the porch--the vestibule leading to the street--no doubt finding the fire-place too hot for him; possibly also with the hope of escaping--but that was not to be, and perhaps he dreaded that, too. Doubtless by this time his mind would be getting into a sea of commotion, and would fluctuate every moment in its resolves.

AND THE COCK CREW--(See on Lu 22:34). This, then, was the First Denial.

Peter's Second Denial of His Lord (Mr 14:69, 70).

There is here a verbal difference among the Evangelists, which without some information which has been withheld, cannot be quite extricated.