The apostle John's account of the crucifixion of our Savior includes significant details that the other gospels omit. John filled his gospel with signs and proofs that Jesus was the Messiah, often drawing attention to His fulfillment of various scriptures. For example, in verse 28, John records Jesus saying, "I thirst!" in reference to Psalm 22:15, a well-known Messianic psalm. He prefaces this quotation with "that the Scripture might be fulfilled." Previous chapters contain numerous examples of this.
Notice, however, verse 36, which adds a crucial detail: "For these things were done that the Scripture should be fulfilled, 'Not one of His bones shall be broken.'" Part of the cruelty of crucifixion was the position of the arms in relation to the rest of the body. Because the victim was nailed up with his arms above his head, his upper ribcage was compressed, making it hard for him to breathe. Anyone who has hung from a branch or a bar knows that his lungs became constricted. The longer a person hangs without pulling up—especially if his hands are close together—the more he feels like he will run out of air.
In a crucifixion, the victim was severely abused before being nailed up, so he, already weakened, would have difficulty pulling himself up to breathe. But not wanting the misery to end too soon, the executioners would give him some painful help by nailing his feet to the stake, too. In this way, if he could suffer the agony of putting all his weight on his impaled feet, he could push himself up with his legs and breathe easier for as long as he could endure that position.
However, if the execution needed to end more quickly, the executioners would break the victim's legs so he could not push himself up. Death followed shortly thereafter. This leg-breaking is what almost happened with Jesus. The Jews, hypocritically not wanting their murder of the Son of God to interfere with their keeping of the holy day, requested that the Romans break the legs of those being crucified. When they came to Jesus, however, He was already dead. They pierced Him instead, and a Messianic prophecy was fulfilled. And in leaving Christ's legs unbroken, another scripture, Psalm 34:20, was fulfilled.
