Hebrews 9:20

Τοῦτο. In the Hebrew “Behold!” Some have supposed that the writer adopted the variation from a reminiscence of our Lord’s words—“This is my blood of the new covenant which is shed for many for the remission of sins” (Matthew 26:28). But if such a reference or comparison had been at all present to his mind, he would hardly have been likely to pass it over in complete silence.

ἧς ἐνετείλατο πρὸς ὑμᾶς ὁ θεός. “Which God commanded with regard to you,” i.e. which (covenant) Jehovah commanded me to deliver to you.