John Mark
Mark 14:68ESV·traditional attribution

But he denied it, saying, “I neither know nor understand what you mean.” And he went out into the gateway and the rooster crowed.

Matthew Henry Presbyterian @wholebiblehenry

We have here the story of Peter's denying Christ. 1. It began in keeping at a distance from him. Peter had followed afar off (Mar 14:54), and now was beneath in the palace, at the lower end of the hall.

Commenting on Mark 14:66-72

John Gill Reformed Baptist @doctorgill

And the second time the cock crew,.... Immediately, as soon as he had so said and swore, as the Vulgate Latin, Syriac, and Ethiopic versions read, and as it is read in one of Beza's copies; which was about three of the clock in the morning, and is what is properly called the cock crowing: and Peter called to mind; upon hearing the cock crow...