Deuteronomy 8:2-4

21And you shall remember all the way which the Lord your God has 2led you in the wilderness these forty years, in order to humble you, 3putting you to the test, to know what was in your heart, whether you would keep His commandments or not.

3And He humbled you and let you go hungry, and fed you with the manna which you did not know, nor did your fathers know, in order to make you 4understand that 5man shall not live on bread alone, but man shall live on everything that comes out of the mouth of the Lord.

46Your clothing did not wear out on you, nor did your foot swell these forty years.