Ezekiel 3:8-9

Behold, I have made your face as hard as their faces and your forehead as hard as their foreheads. I have made your forehead like emery (diamond), harder than flint. Do not be afraid of them or be dismayed before them, though they are a rebellious house.” [Is 50:7; Jer 1:18; 15:20; Mic 3:8]