Exodus 12:46 - ...neither shall ye break a bone thereof
John 19:33 - But when they came to Jesus, and saw that He was dead already, the brake not His legs.
The verse in Exodus was a commandment from God to not break any bones in the sacrificial passover lamb. This was a symbolic foreshadowing. When the Romans would crucify a person, the victim would not die immediately. While hanging there, they would push themself up using their legs in order to cstch their breath. The Roman soldiers would usually break the legs of the victims hanging on the cross. This would speed up the suffocation and eventual death. But with Jesus, the Roman soldiers realized He was already dead, so they did not break His legs.