Job 41:19 Kabbalah

יַחְשֹׁ֣ב לְתֶ֣בֶן בַּרְזֶ֑ל לְעֵ֖ץ רִקָּב֣וֹן נְחוּשָֽׁה׃

He esteemeth iron as straw, and brass as rotten wood.

Read kabbalistic (mystical) interpretation of Job 41:19: and classical mystical sources.