Hebrews 9:20

Saying, this is the blood of the testament
The first testament or covenant; this proves what the apostle had asserted in ( Hebrews 9:18 ) that it was dedicated with blood, or confirmed by it; compare with this ( Matthew 26:28 )

which God hath enjoined unto you;
the people of Israel, to observe, and which they promised to do; see ( Exodus 24:7 Exodus 24:8 ) .