A.T. Robertson Commentary Luke 22:50

"And a certain one of them smote the servant of the high priest, and struck off his right ear." — Luke 22:50 (ASV)

His right ear (το ους αυτου το δεξιον). Mark 14:47; Matthew 26:51 do not mention "right," but Luke the Physician does. John 18:10 follows Luke in this item and also adds the names of Peter and of Malchus since probably both were dead by that time and Peter would not be involved in trouble.