68 But Peter denied it. "I don't know what you're talking about," he said, and he went out into the entryway. Just then, a rooster crowed. 69 When the servant girl saw him standing there, she began telling the others, "This man is definitely one of them!" 70 But Peter denied it again. A little later some of the other bystanders confronted Peter and said, "You must be one of them, because you are a Galilean." 71 Peter swore, "A curse on me if I'm lying-I don't know this man you're talking about!" 72 And immediately the rooster crowed the second time. Suddenly, Jesus' words flashed through Peter's mind: "Before the rooster crows twice, you will deny three times that you even know me." And he broke down and wept.
Matthew Henry's Commentary on Mark 14:68-72
Commentary on Mark 14:66-72
(Read Mark 14:66-72)
Peter's denying Christ began by keeping at a distance from him. Those that are shy of godliness, are far in the way to deny Christ. Those who think it dangerous to be in company with Christ's disciples, because thence they may be drawn in to suffer for him, will find it much more dangerous to be in company with his enemies, because there they may be drawn in to sin against him. When Christ was admired and flocked after, Peter readily owned him; but will own no relation to him now he is deserted and despised. Yet observe, Peter's repentance was very speedy. Let him that thinketh he standeth take heed lest he fall; and let him that has fallen think of these things, and of his own offences, and return to the Lord with weeping and supplication, seeking forgiveness, and to be raised up by the Holy Spirit.