Deuteronomy 8:9

8:9 a land where you may eat food in plenty and find no lack of anything, a land whose stones are iron and from whose hills you can mine copper.

Deuteronomy 28:48

28:48 instead in hunger, thirst, nakedness, and poverty you will serve your enemies whom the Lord will send against you. They will place an iron yoke on your neck until they have destroyed you.