Adam Clarke on Matthew 26:51

One of them which were with Jesus - This was Peter - struck a servant of the high priest's, the servant's name was Malchus, Joh 18:10, and smote off his ear. In Luk 22:51, it is said, Jesus touched and healed it. Here was another miracle, and striking proof of the Divinity of Christ. Peter did not cut the ear, merely, he cut it Off, αφειλεν. Now to heal it, Jesus must either take up the ear and put it on again, or else create a new one - either of these was a miracle, which nothing less than unlimited power could produce. See the note on Joh 18:10.