WCF 29.2.
In this sacrament, Christ is not offered up to His Father; nor any real sacrifice made at all, for remission of sins of the quick or dead; (Heb. 9:22, 25–26, 28) but only a commemoration of that one offering up of Himself, by Himself, upon the cross, once for all: and a spiritual oblation of all possible praise unto God, for the same: (1 Cor. 11:24–26, Matt. 26:26–27) so that the popish sacrifice of the mass (as they call it) is most abominably injurious to Christ’s one, only sacrifice, the only propitiation for all the sins of His elect. (Heb. 7:23–24, 27, Heb. 10:11–12, 14, 18)