John Calvin Commentary John 11:55

"Now the passover of the Jews was at hand: and many went up to Jerusalem out of the country before the passover, to purify themselves." — John 11:55 (ASV)

Many from that country went up to Jerusalem. It was not absolutely required that they should purify themselves before sacrificing the Passover; and therefore, the Evangelist does not say that all came, but many. No unclean person, indeed, was permitted to eat; but I say that this sanctification was undertaken voluntarily and from their own inclination, so that others were not forbidden to eat, though they had not been prepared by such a ceremony before the day of the feast.