Adam Clarke

For by one offering - His death upon the cross. He hath perfected for ever - He has procured remission of sins and holiness; fur it is well observed here, and in several parts of this epistle, that τελειοω, to make perfect, is the same as αφεσιν ἁμαρτιων ποιεω, to procure remission of sins. Them that are sanctified - Τους ἁγιαζομενους· Them that have received the sprinkling of the blood of this offering. These, therefore, receiving redemption through that blood, have no need of any other offering; as this was a complete atonement, purification, and title to eternal glory.