Peter denied three times that he knew Jesus.

Matthew 26:69-75

69 Peter was sitting outside in the courtyard. A servant girl came up to him and looked at him. She said, “You also were with Jesus, that man from Galilee district!” 70 But while everyone there was listening, he denied it. He said, “I do not know what you are talking about!” 71 Then he went out to the gateway of the courtyard. Another servant girl saw him and said to the people who were standing nearby, “This man was with Jesus, the man from Nazareth.” 72 But Peter again denied it. He said, “May God punish me if I am lying! I tell you, I do not even know that man!” 73 After a little while, one of the people who were standing there approached Peter and said to him, “It is certain that you are one of those who were with that man. We can tell from your accent that you are from Galilee.” 74 Then Peter began to proclaim loudly that God should curse him if he was lying. He asked God in heaven to witness that he was telling the truth and said, “I do not know that man!” Immediately a rooster crowed. 75 Then Peter remembered the words that Jesus had spoken to him, “Before the rooster crows, you will say three times that you do not know me.” And Peter went out of the courtyard, crying because he was very sad about what he had done.