Christ's last passover, which was the fourth after he had entered upon his public ministry, was nigh. He doth not say all, but many went up to purify themselves. There was no general legal purification required before men did eat the passover; but there were several legal uncleannesses, and purifications necessary to cleanse men from them; now those who had any special purification to pass, went before others, that they might have time to do what the law required of them.
Related Commentaries of John 11:55
John 11:55
55 And the Jews' passover was nigh at hand: and many went out of the country up to Jerusalem before the passover, to purify themselves.