Expositor's Bible Commentary Commentary John 19:37

"And again another scripture saith, They shall look on him whom they pierced." — John 19:37 (ASV)

One of the soldiers pierced Jesus’ side with his spear, probably to see whether there would be any reaction. The flow of “blood and water” has been variously explained. Ordinarily dead bodies do not bleed because there is no action of the heart to produce arterial pressure. One suggestion is that since the body was erect, the flow was due to gravity and that the crassamentum (the heavy, red corpuscles) and the serum (the yellowish white aqueous part) of the blood had already begun to separate. Another is that either the stomach or the lungs contained water that flowed with the blood. The author places great importance on this fact, emphasizing that he had witnessed it for himself and that he was telling the truth. He connects the fact that no bones were broken with Ex 12:46; Psalms 34:20 and the pierced side with Zec 12:10 (where that fact is related to the final manifestation of the Lord to Israel). Verses 35–37 are a footnote giving the author’s viewpoint in the third person, a usage in keeping with his practice throughout the gospel.