Pseudo-Jerome
Catena Aurea · Markusevangelium 14
And they came to a place which was named Gethsemane: and he saith to his disciples, Sit ye here, while I shall pray. And he taketh with him Peter and James and John, and began to be sore amazed, and to be very heavy; And saith unto them, My soul is exceeding sorrowful unto death: tarry ye here, and watch. And he went forward a little, and fell on the ground, and prayed that, if it were possible, the hour might pass from him. And he said, Abba, Father, all things are possible unto thee; take away this cup from me: nevertheless not what I will, but what thou wilt. And he cometh, and findeth them sleeping, and saith unto Peter, Simon, sleepest thou? couldest not thou watch one hour? Watch ye and pray, lest ye enter into temptation. The spirit truly is ready, but the flesh is weak. And again he went away, and prayed, and spake the same words. And when he returned, he found them asleep again, (for their eyes were heavy,) neither wist they what to answer him. And he cometh the third time, and saith unto them, Sleep on now, and take your rest: it is enough, the hour is come; behold, the Son of man is betrayed into the hands of sinners. Rise up, let us go; lo, he that betrayeth me is at hand.
The threefold sleep of the disciples points out the three dead, whom our Lord raised up; the first, in a house; the second, at the tomb; the third, from the tomb. And the threefold watch of the Lord teaches us in our prayers, to beg for the pardon of past, future, and present sins.