For where a will is involved, the death of the one who made it must be established.
16. For where a testament is, etc. Even this one passage is a sufficient proof, that this Epistle was not written in Hebrew; for ברית means in Hebrew a covenant, but not a testament; but in Greek, διαθήκη, includes both ideas; and the Apostle, alluding to its secondary meaning, holds that the promises should not have been otherwise ratified and valid, had they not been...
In these verses the apostle considers the gospel under the notion of a will or testament, the new or last will and testament of Christ, and shows the necessity and efficacy of the blood of Christ to make this testament valid and effectual. I. The gospel is here considered as a testament, the new and last will and testament of our Lord and Saviour Jesus Christ.
Commenting on Hebrews 9:15-22
For where a testament is,.... The covenant of grace, as administered under the Gospel dispensation, is a testament or will. The Jews have adopted the Greek word, here used, into their language, and pronounce it and by it understand a dying man's last will and testament (d).