Bede the Venerable
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.
Let no one ascribe this sweat to natural weakness, nay, it is contrary to nature to sweat blood, but rather let him derive therefrom a declaration to us, that He was now obtaining the accomplishment of His prayer, namely, that He might purge by His blood the faith of His disciples, still convicted of human frailty.