כְּשָׁמִ֛יר חָזָ֥ק מִצֹּ֖ר נָתַ֣תִּי מִצְחֶ֑ךָ לֹֽא־תִירָ֤א אוֹתָם֙ וְלֹא־תֵחַ֣ת מִפְּנֵיהֶ֔ם כִּ֛י בֵּֽית־מְרִ֖י הֵֽמָּה׃ (פ)
Comme le diamant plus dur que le roc, je ferai ton front. Tu n’auras pas peur d’eux, tu ne trembleras pas à cause d’eux, parce qu’ils sont une maison de rébellion.
Rashi
with a pen of iron This is an allegory. That is to say that it is deeply engraved, and cannot be erased. And the Midrash Aggadah explains: with a pen of iron, with a diamond point, preserved by Jeremiah, called ‘an iron wall,’ and by Ezekiel, to whom it was said (3:9): “As a diamond, harder than flint have I made your forehead.”
Rashi
the shamir and desolation will come up Heb. שָׁמִיר וָשָׁיִת. Menahem ben Seruk interprets them as kinds of thorns (Machbereth Menahem p. 176), but I say that “shamir” is a word denoting a strong worm that splits stones, with which Solomon built the Temple, like the matter that is written (Ezekiel 3:19), “Like a shamir, stronger than rock.”
Chizkuni
צר, a sharp scalpel. Compare Joshua 5,2 חרבות צורים, according to Rash’bam. An alternate interpretation: the word צר means “stone;” we find it as having this meaning also in Ezekiel 3,9: כשמיר חזק מצור, like a shamir, “even harder than rock.” She took what was at hand.