TgJ Is48:4 :קשֵי כְבַרזְלָא קְדָלָך וֻבֵית עֵינָך חַסִין כִנחָשָא‏ : your neck is as hard as iron, your forehead as firm as bronze
See the entire entry for bēṯ ˁaynīn, bēṯ ˁaynē n.m. forehead

TgJ Is48:4 :דְאַת סָרְבָן וֻקשֵי כְבַרזְלָא קְדָלָך‏ : you are stubborn and your neck is as hard as iron
See the entire entry for qəšē adj. hard