John 19:31–37 (NKJV)
31 Therefore, because it was the Preparation Day, that the bodies should not remain on the cross on the Sabbath (for that Sabbath was a high day), the Jews asked Pilate that their legs might be broken, and that they might be taken away. 32 Then the soldiers came and broke the legs of the first and of the other who was crucified with Him. 33 But when they came to Jesus and saw that He was already dead, they did not break His legs. 34 But one of the soldiers pierced His side with a spear, and immediately blood and water came out. 35 And he who has seen has testified, and his testimony is true; and he knows that he is telling the truth, so that you may believe. 36 For these things were done that the Scripture should be fulfilled, “Not one of His bones shall be broken.” 37 And again another Scripture says, “They shall look on Him whom they pierced.”John 19:31-37
Per Jewish custom, prisoners being executed were not to stay on a cross past Friday at sundown. This was the official beginning of the Sabbath day observance. Because of that, the Jews asked for the prisoners’ legs to be broken, which would make breathing much more difficult and hasten their death. The two thieves crucified with Jesus had their legs broken, but when they came to Jesus, it appeared He was already dead, therefore His legs were not broken. This is significant due to the prophecy that not one of the Messiah’s bones would be broken. Then, one of the soldiers took a spear and pierced His side, where water and blood came out. This signified that His heart or at least His pleural sac had ruptured. It also fulfilled a Biblical prophecy that they would see Him pierced.
All of this scene proved to establish that Jesus is the Messiah. This is another piece of the prophetic puzzle making it clear that Jesus is the Son of God, and the Savior of the world. While the Jews rejected the notion of Jesus being their Messiah, He died for their sins and the sins of all the world. He died for you and me. He fulfilled all that the Father intended for Him. He made a way for anyone to be saved if they believe. The spear in His side was one more sign that He was truly Who He said He was! Thank God He was willing to go all the way to the cross and beyond to save us.
Artwork by http://crossbearer-brian.tripod.com/id69.htm