Seven years of abundance are about to come in the whole land of Egypt.
The seven good cows: they are seven years. Also the seven ears of corn: they’re seven years. It is one dream.
Then seven years of famine will come up after them and all the abundance in the land of Egypt will be forgotten and the famine will consume the land.
So Joseph stored up grain like the sand of the sea, vast amounts, until he stopped keeping record because it was beyond counting.