Deuteronomy 8:14-16

14then your heart will become lifted up [by self-conceit and arrogance] and you will forget the Lord your God who brought you from the land of Egypt, out of the house of slavery.

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

16He fed you manna in the wilderness, [a substance] which your fathers did not know, so that He might humble you [by dependence on Him] and that He might test you, to do good [things] for you at the end.