The sense seems to be that, owing to his position in the nation, the priest is not to defile himself in any cases except those named in ([Reference…

But he shall not defile himself, being a chief man ... — Better, A husband shall not defile himself among his people when he h…

[But] he shall not defile himself, [being] a chief man among
his people

As these priests were types of Christ, so all ministers must be followers of him, that their example may teach others to imitate the Saviour. Witho…