John 19:34
One of the soldiers with a spear opened His side, and immediately there came out blood and water.
Haydock
Verse 34. There came out blood and water, which naturally could not come from a dead body. Wi. — Hence it is, that the sacred mysteries flow; as often, therefore, as thou approachest the awful cup, approach it as if thou wert going to drink from thy Saviour’s sacred side. S. Chrys. hom. lxxxiv. in Joan. — The holy Fathers say, that the spouse of Jesus Christ was here taken out of his side, whilst sleeping on the cross, as Eve was from Adam’s side, when he was cast asleep in Paradise.
Denzinger
945: The Water to be Mixed with Wine to be Offered in the Chalice
The Council of Trent SESSION XXII (Sept. 17, 1562) The Doctrine on the Most Holy Sacrifice of the Mass
The holy Synod then admonishes priests that it has been prescribed by the Church to mix water with the wine to be offered in the chalice [can. 9], not only because the belief is that Christ the Lord did so, but also because there came from His side water together with blood [John 19:34], since by this mixture the sacrament is recalled. And since in the Apocalypse of the blessed John the peoples are called waters [Rev. 17:1, 15], the union of the faithful people with Christ, their head, is represented.
Catena Aurea
31. The Jews therefore, because it was the preparation, that the bodies should not remain upon the cross on the sabbath day, (for that sabbath day was an high day,) besought Pilate that their legs might be broken, and that they might be taken away. 32. Then came the soldiers, and brake the legs of the first, and of the other which was crucified with him. 33. But when they came to Jesus, and saw that he was dead already, they brake not his legs: 34. But one of the soldiers with a spear pierced his side, and forthwith came there out blood and water. 35. And he that saw it bare record, and his record is true: and he knoweth that he saith true, that ye might believe. 36. For these things were done, that the Scripture should be fulfilled, A bone of him shall not be broken. 37. And again another Scripture saith, They shall look on him whom they pierced.
CHRYSOSTOM. (Hom. lxxxv) The Jews who strained at a gnat and swallowed a camel, after their audacious wickedness, reason scrupulously about the day: The Jews therefore because it was the preparation, that the bodies should not remain upon the cross on the sabbath.
BEDE. Parasceue, i. e. preparation: the sixth day was so called because the children of Israel prepared twice the number of loaves on that day. For that sabbath day was an high day, i. e. on account of the feast of the passover.
Besought Pilate that their legs might be broken.
AUGUSTINE. (Tr. cxx) Not in order to take away the legs, but to cause death, that they might be taken down from the cross, and the feast clay not be defiled by the sight of such horrid torments.
THEOPHYLACT. For it was commanded in the Law that the sun should not set on the punishment of any one; or they were unwilling to appear tormentors and homicides on a feast day.
CHRYSOSTOM. (Hom. lxxxv. 3) How forcible is truth: their own devices it is that accomplish the fulfilment of prophecy: Then came the soldiers and brake the legs of the first, and of the other which was crucified with Him. But when they came to Jesus, and saw that He was dead already, they brake not His legs: but one of the soldiers with a spear pierced His side.
THEOPHYLACT. To please the Jews, they pierce Christ, thus insulting even His lifeless body. But the insult issues in a miracle: for a miracle it is that blood should flow from a dead body.
AUGUSTINE. (Tr. cxx.) The Evangelist has expressed himself cautiously; not struck, or wounded, but opened His side: (ἔνυξε, aperuit V.) whereby was opened the gate of life, from whence the sacraments of the Church flowed, without which we cannot enter into that life which is the true life: And forthwith came thereout blood and water. That blood was shed for the remission of sins, that water tempers the cup of salvation. This it was which was prefigured when Noah was commanded to make a door in the side of the ark, by which the animals that were not to perish by the deluge entered; which animals prefigured the Church. To shadow forth this, the woman was made out of the side of the sleeping man; for this second Adam bowed His head, and slept on the cross, that out of that which came therefrom, there might be formed a wife for Him. O death, by which the dead are quickened, what can be purer than that blood, what more salutary than that wound!
CHRYSOSTOM. (Hom. lxxxv) This being the source whence the holy mysteries are derived, when thou approachest the awful cup, approach it as if thou wert about to drink out of Christ’s side.
THEOPHYLACT. Shame then upon them who mix not water with the wine in the holy mysteries: they seem as if they believed not that the water flowed from the side. Had blood flowed only, a man might have said that there was some life left in the body, and that that was why the blood flowed. But the water flowing is an irresistible miracle, and therefore the Evangelist adds, And he that saw it bare record.
CHRYSOSTOM. (Hom. lxxxv. 3) As if to say, I did not hear it from others, but saw it with mine own eyes. And his record is true, he adds, not as if he had mentioned something so wonderful that his account would be suspected, but to stop the mouths of heretics, and in contemplation of the deep value of those mysteries which he announces.
And he knoweth that he saith true, that ye might believe.
AUGUSTINE. (Tr. cxx) He that saw it knoweth; let him that saw not believe his testimony. He gives testimonies from the Scriptures to each of these two things he relates. After, they brake not His legs, He adds, For these things were done, that the Scripture should be fulfilled, A bone of Him shall not be broken, a commandment which applied to the sacrifice of the paschal lamb under the old law, which sacrifice foreshadowed our Lord’s. Also after, One of the soldiers with a spear opened His side, then follows another Scripture testimony; And again another Scripture saith, They shall look on Him whom they pierced, (Zech. 12:10) a prophecy which implies that Christ will come in the very flesh in which He was crucified.
JEROME. (Pref. ad Pentet.) This testimony is taken from Zacharias.