Hebrews 9:16,17

Heb. 9:16-17. For where a testament (is), there must also of necessity be the death of the testator. For a testament (is) of force after men are dead; otherwise it is of no strength at all while the testator liveth.

Another reference to Heb. 9 is found in "The Peace which Christ Gives to His True Followers."

This covenant between Christ and his children is like a will or testament also in this respect, that it becomes effectual by, and no other way than by, his death; as the apostle observes it is with a will or testament among men. For a testament is of force after men are dead, Hebrews 9:17. For though the covenant of grace indeed was of force before the death of Christ, yet it was of force no otherwise than by his death. So that his death then did virtually intervene; being already undertaken and engaged. As a man's heirs come by the legacies bequeathed to them no otherwise than by the death of the testator, so men come by the spiritual and eternal inheritance no otherwise than by the death of Christ. If it had not been for the death of Christ they never could have obtained it.

Heb. 9:18-19