tsor denotes a hard stone used for cutting and for comparison with an unyielding forehead.

The two verses show tsor as a hard stone: in Exodus 4:25 it is taken for a cutting action, while in Ezekiel 3:9 it supplies the comparison for a forehead made hard against a rebellious house.

1. Hard stone for cutting and comparison · dominant

   Both occurrences use the masculine singular absolute noun for a hard stone. In Exodus 4:25 the APB renders that Zipporah took “a flint” and cut off her son's foreskin; in Ezekiel 3:9 it renders the forehead as “like the hardest flint,” describing resolve not to fear or be dismayed.

   Exodus 4:25Ezekiel 3:9

In the Anselm Project Bible: The APB presents the term as “a flint” in Exodus 4:25 and “the hardest flint” in Ezekiel 3:9. These renderings confirm the verses' hard-stone imagery without fixing every nuance of the Hebrew term.