Deuteronomy 8:2-4

LITV(i) 2 And you shall remember all the way which Jehovah your God has caused you to go these forty years in the wilderness, in order to humble you, to try you, to know that which is in your heart, whether you will keep His commandments or not. 3 And He has humbled you, and caused you to hunger, and caused you to eat the manna, which you had not known, and your fathers had not known, in order to cause you to know that man shall not live by bread alone, but man shall live by every word that proceeds from the mouth of Jehovah. 4 Your clothing did not wear out on you, and your foot did not swell, these forty years.