Now was there any thing of this but in fulfilling of the Scripture; for it was God's law about the passover, Exodus 12:46 Numbers 9:12, concerning the paschal lamb, (which was a type of Christ, 1 Thessalonians 1:29 1 Corinthians 5:7), that a bone of it should not be broken. So as by this breaking no bone of Christ's body, they might have understood that he was figured out by the paschal lamb.
Related Commentaries of John 19:36
John 19:36
36 For these things were done, that the scripture should be fulfilled, A bone of him shall not be broken.