Giovanni 19:34

But one of the soldiers with a spear pierced his side, and forthwith came there out blood and water. With a spear pierced his side - The soldier who pierced our Lord's side has been called by the Roman Catholic writers Longinus, which seems to be a corruption of λογχη, lonche, a spear or dart, the word in the text. They moreover tell us that this man was converted - that it was he who said, Truly this was the Son of God - that he traveled into Cappadocia, and there preached the Gospel of Christ, and received the crown of martyrdom. But this deserves the same credit as the other legends of the Popish Church.

Whether it was the right or the left side of Christ that was pierced has been a matter of serious discussion among divines and physicians; and on this subject they are not yet agreed. That it is of no importance we are sure, because the Holy Ghost has not revealed it. Luke Cranache, a famous painter, whose piece of the crucifixion is at Augsburg, has put no wound on either side: when he was asked the reason of this - I will do it, said he, when I am informed Which side was pierced.

Blood and water - It may be naturally supposed that the spear went through the pericardium and pierced the heart; that the water proceeded from the former, and the blood from the latter. Ambrose, Augustin, and Chrysostom, make the blood an emblem of the eucharist, and the water an emblem of baptism. Others represent them as the emblems of the old and new covenants. Protestants have thought them the emblems of justification, which is through the blood of the Lamb, and sanctification, which is through the washing of regeneration; and it is in reference to the first notion that they mingle the wine with water in the sacrament of the Lord's supper.

The piercing appears to have taken place because his legs were not broken; and, as the law in this case stated that the criminals were to continue on the cross till they died, the side of our Lord was pierced to secure the accomplishment of the law; and the issuing of the blood and water appears to be only a natural effect of the above cause, and probably nothing mystical or spiritual was intended by it.

However, it affords the fullest proof that Jesus died for our sins. Dr. Lightfoot thinks that there is a reference here to the rock in the wilderness which Moses smote twice, and which, according to the Jews, Shemoth Rabba, fol. 122, "poured out blood at the first stroke, and water at the second." Now St. Paul says, 1 Corinzi 10:4, That rock was Christ; and here the evangelist says, the soldier pierced his side, and there came out blood and water.

St. John therefore, in what he asserts in the 35th and 36th verses, wishes to call the attention of the Jews to this point, in order to show them that this Jesus was the true Messiah, who was typified by the rock in the wilderness. He knoweth that he saith true, that ye might believe.