Mark 14

Knowing that Mark learned much of his gospel or story from Peter, he writes -

"...as Peter was beneath in the palace, there cometh one of the maids of the high priest:
67 And when she saw Peter warming himself, she looked upon him, and said, And thou also wast with Jesus of Nazareth.
68 But he denied, saying, I know not, neither understand I what thou sayest. And he went out into the porch; and the cock crew.
69 And a maid saw him again, and began to say to them that stood by, This is one of them.
70 And he denied it again. And a little after, they that stood by said again to Peter, Surely thou art one of them: for thou art a Galilæan, and thy speech agreeth thereto.
71 But he began to curse and to swear, saying, I know not this man of whom ye speak.
72 And the second time the cock crew. And Peter called to mind the word that Jesus said unto him, Before the cock crow twice, thou shalt deny me thrice. And when he thought thereon, he wept."  (Mark 14:66–72)

I believe this is the testimony of Peter