But when they came to Jesus, and saw that he was dead already, they brake not his legs:

Jamieson-Fausset-Brown Bible Commentary

33. But when they came to Jesus, and saw that he was dead already-there being in His case elements of suffering, unknown to the malefactors, which might naturally hasten His death, lingering though it always was in such cases, not to speak of His previous sufferings.

they brake not his legs-a fact of vast importance, as showing that the reality of His death was visible to those whose business it was to see to it. The other divine purpose served by it will appear presently.

Matthew Henry's Concise Commentary

19:31-37 A trial was made whether Jesus was dead. He died in less time than persons crucified commonly did. It showed that he had laid down his life of himself. The spear broke up the very fountains of life; no human body could survive such a wound. But its being so solemnly attested, shows there was something peculiar in it. The blood and water that flowed out, signified those two great benefits which all believers partake of through Christ, justification and sanctification; blood for atonement, water for purification. They both flow from the pierced side of our Redeemer. To Christ crucified we owe merit for our justification, and Spirit and grace for our sanctification. Let this silence the fears of weak Christians, and encourage their hopes; there came both water and blood out of Jesus' pierced side, both to justify and sanctify them. The Scripture was fulfilled, in Pilate's not allowing his legs to be broken, Ps 34:20. There was a type of this in the paschal lamb, Ex 12:46. May we ever look to Him, whom, by our sins, we have ignorantly and heedlessly pierced, nay, sometimes against convictions and mercies; and who shed from his wounded side both water and blood, that we might be justified and sanctified in his name.