Ezekiel 3:7

For thou art not sent to a people of a strange speech and of an hard language, but to the house of Israel;

Not to many people of a strange speech and of an hard language, whose words thou canst not understand. Surely, had I sent thee to them, they would have hearkened unto thee.

Behold, I have made thy face strong against their faces, and thy forehead strong against their foreheads.

As an adamant harder than flint have I made thy forehead: fear them not, neither be dismayed at their looks, though they be a rebellious house.