Theophylact of Ohrid
Catena Aurea · Lukasevangelium 22
And there appeared an angel unto him from heaven, strengthening him. And being in an agony he prayed more earnestly: and his sweat was as it were great drops of blood falling down to the ground. And when he rose up from prayer, and was come to his disciples, he found them sleeping for sorrow. And said unto them, Why sleep ye? rise and pray, lest ye enter into temptation.
Now that the preceding prayer was of His human nature, not His divine, as the Arians say, is argued from what is said of His sweat, which follows, And his sweat was as it were great drops of blood falling down to the ground.