Luke 22:44

And being in agony he prayed more earnestly; and his sweat became as it were great drops of blood falling down upon the ground.

The Greek word for "drops of blood" is [@thromboi], used only here in the New Testament. "It means clots of blood"[26] and was used by the physician Luke in the same manner as was common in ancient medical works. The spiritual overtones of this were noted by Henry, thus:

Sweat came in with sin, and was a branch of the curse (Genesis 3:19). When Christ was made sin and a curse for us, he underwent a grievous sweat, that in the sweat of his face we might eat the bread of life.[27]

Regarding this blood-sweat, it is a mistake to suppose any exaggeration here.

Aristotle (Hist. Anita. said that in certain extraordinary states the blood becomes very liquefied and flows in such a manner that some have perspired blood.[28]

Moreover, the phenomena is not unknown to modern physicians. Dummelow said that "Great mental agony has been known to produce this phenomenon."[29] The fact that death usually followed very quickly after such a blood-sweat suggests the necessity of the angel's mission to strengthen Jesus, who himself described his condition as being "exceedingly sorrowful, even unto death" (Matthew 26:38).

[26] Herschel H. Hobbs, op. cit., p. 312.

[27] Matthew Henry and Thomas Scott, Commentary on the Holy Bible (Grand Rapids, Michigan: Baker Book House, 1960), p. 309.

[28] George R. Bliss, op. cit., p. 323.

[29] J. R. Dummelow, op. cit., p. 767.