John Lightfoot on John 19:36

[A bone of him shall not be broken.] These words may have some reference to that of Psalm 34:20: but they are more commonly referred by expositors to that law about the Paschal lamb, Exodus 12:46: for "Christ is our Passover," 1 Corinthians 5:7.

"If any one break a bone of the Passover, let him receive forty stripes." "The bones, the sinews, and what remains of the flesh, must all be burned on the sixteenth day. If the sixteenth day should happen on the sabbath" [and so indeed it did happen in this year wherein Christ was crucified], "then let them be burned on the seventeenth: for they drive away neither the sabbath nor any holy day."