A.T. Robertson Commentary John 19:31

"The Jews therefore, because it was the Preparation, that the bodies should not remain on the cross upon the sabbath (for the day of that sabbath was a high [day]), asked of Pilate that their legs might be broken, and [that] they might be taken away." — John 19:31 (ASV)

The Preparation (παρασκευη). Friday. See verse 14.

Might not remain (μη μεινη). Negative final clause with ινα μη and first aorist active (constative) subjunctive of μενω.

A high day (μεγαλη). A "great" day, since "the sabbath day following synchronized with the first day of unleavened bread which was a 'great' day" (Bernard). A double reason therefore for wanting the bodies removed before sunset when the Sabbath began.

That their legs might be broken (ινα κατεαγωσιν αυτον τα σκελη). Purpose clause with ινα and the second aorist passive subjunctive of καταγνυμ with the augment retained in the subjunctive, a "false augment" common in later Greek as in the future in Mt 12:20 with this verb (Robertson, Grammar, p. 365). This crurifragium was done with a heavy mallet and ended the sufferings of the victim.

Legs (σκελη). Old word, here only in N.T.

Might be taken away (αρθωσιν). First aorist passive subjunctive of αιρω with ινα also.