Deuteronomy 8:15-16

15He led you through 1the great and terrible wilderness, with its 2fiery serpents and scorpions and thirsty ground where there was no water; He 3brought water for you out of the rock of flint.

16In the wilderness He fed you manna 4which your fathers did not know, that He might humble you and that He might 5test you, to do good for you 6in the end.