ametathetos describes what is presented as fixed and not subject to change in God’s plan and the two things named with it.

The two occurrences describe what is fixed rather than subject to change: God’s plan in Hebrews 6:17 and the two things through which encouragement is given in Hebrews 6:18.

1. Fixed character of God’s plan and assurance · dominant

   In Hebrews 6:17, the accusative singular neuter form qualifies the character of God’s plan, which the APB renders as “the unchangeable character of his plan.” In Hebrews 6:18, the genitive plural neuter form occurs with “two” things, rendered by the APB as “two unchangeable things,” in a statement about encouragement and hope.

   Hebrews 6:17Hebrews 6:18

In the Anselm Project Bible: The APB uses “unchangeable” in both verses, first for the character of God’s plan and then for two things. These renderings confirm the clauses’ presentation rather than isolate every feature of the term.