Devarim 33:25

ברזל ונחשת מנעלך THY LOCKS SHALL BE IRON AND COPPER — He is now addressing all Israel: This prophecy was fulfilled because their mighty men used to dwell in the border cities and, as it were, locked it (the country) so that the enemy should not be able to invade it, as though it were closely shut by locks and bars of iron and copper. Another explanation of ברזל ונחשת מנעלך: your land is locked in (surrounded) by mountains from which iron and copper is hewn, and the country of Asher was the “lock” of the Land of Israel (Sifrei Devarim 355:25). וכימיך דבאך AND AS THY DAYS SO SHALL BE דבאך — i.e. and as the days that are thy best, — that is, the days of thy beginning, the days of thy youth, so shall be the days of thy old age, which דואבים, i.e. which flow away and decline (דבאך therefore means: the period of thy decline). Another explanation of וכימיך דבאך: as the number of thy days — all the days when thou didst perform the will of the Omnipresent, — shall be דבאך, thy flowing, i.e., referring to the fact that all countries will make gold and silver flow into the land of Israel, because it will be blessed with fruits, and all countries will take their supply of fruit from it and will, in payment, pour into it their silver and gold; askorant in old French: thus their silver and gold will come to an end, because they will pour it into your land (Sifrei Devarim 355:26).

בַּרְזֶ֥ל וּנְחֹ֖שֶׁת מִנְעָלֶ֑ךָ וּכְיָמֶ֖יךָ דׇּבְאֶֽךָ׃

Thy shoes shall be iron and brass; and as thy days, so shall thy strength be.