Thy shoes shall be iron and brass; and as thy days, so shall thy strength be. Deuteronomy 33:25
“Your shoes shall be iron and brass” is used metaphorically to mean “You will have plenty of good leather to make shoes.” In the East the shortage of shoes is one of the greatest problems.
Thousands of men, women, and children walk barefooted. Many workers cut grass and work in the fields barefooted. Only the rich and the princes have more than one pair of shoes.
Moreover, when the shoes are well made, the merchants say, “They are like iron,” which means they are durable. Then again, in the East, shoes are a sign of prosperity. Those who have shoes are well dressed and fed. The tribe of Asher was to have oil, food, and leather for shoes. And they were to be healthy and strong all the days of their lives. God’s blessings were to provide for all their needs. [Note: The verse above was part of Asher's tribal blessing.]
(Lamsa, George M. 1964. Old Testament Light. San Francisco: Harper Collins., pgs 280-281)