Charles Ellicott Commentary Ezekiel 3:9

"As an adamant harder than flint have I made thy forehead: fear them not, neither be dismayed at their looks, though they are a rebellious house." — Ezekiel 3:9 (ASV)

An adamant harder than flint. — Adamant is the diamond, as it is translated (Jeremiah 17:1). The people were as hard as flint, but as the diamond cuts flint, so Ezekiel’s words would, by Divine power, be made to cut through all their resistance. Armed with this strength, he need not fear their obduracy, however great.