Hebrews 9:16

Testament. Greek diatheke. This word may mean either “covenant” or “testament” in the sense of “will” (see on Hebrews 7:22; Galatians 3:15). In Hebrews 9:15-18 there is a play on the two meanings of this word. The “inheritance” mentioned in v. 15 probably suggested the idea of a will or testament, and the phrase “by means of death,” literally, “death having occurred,” probably called to mind the fact that Christ died leaving us an inheritance, and that this inheritance was left us in a testament.

Of necessity. A will has no force whatever so long as the testator lives. For it to become effective, the testator must die.