The physical passion of Christ began in Gethsemane. Of the many aspects of His initial suffering, the one which is of particular physiological interest is the bloody sweat. Interestingly enough, the physician, St. Luke, is the only evangelist to mention this occurrence. He says, “And being in an agony, he prayed the longer. And his sweat became as drops of blood, trickling down upon the ground” (Luke 22:44 KJV).