The priests and the Levites purified themselves - This consisted in washings, abstinence from wine, and other matters, which, on all other occasions, were lawful. And as to the purifying of the gates and the walls, nothing was requisite but to remove all filth from the former, and all rubbish that might have been laid against the latter.

And the priests and the Levites purified themselves,.... By washing their bodies and their clothes, perhaps by sprinkling the water of purification on them, see Numbers 8:6.

The dedication began with the purification of the people, the gates, and the wall, by the priests and Levites, after they had purified themselves. This was probably done, judging from the analogy of 2 Chronicles 29:20, by the offering of sin-offerings and burnt-offerings, according to some special ritual unknown to us, as sacrifices of purification and dedication. This was followed by the central-point of the solemnity, a procession of two bands of singers upon the wall (Nehemiah 12:31-42).

And the priests and the Levites purified themselves, and purified the people, and the gates, and the wall.

12:30 Purified themselves - They that would be instrumental to sanctify others, must sanctify themselves, and set themselves apart for God, with purity of mind and sincerity of intention.

12:27-43 All our cities, all our houses, must have holiness to the Lord written upon them. The believer should undertake nothing which he does not dedicate to the Lord. We are concerned to cleanse our hands, and purify our hearts, when any work for God is to pass through them. Those that would be employed to sanctify others, must sanctify themselves, and set themselves apart for God. To those who are sanctified, all their creature-comforts and enjoyments are made holy. The people greatly rejoiced. All that share in public mercies, ought to join in public thanksgivings.