Genesis 41:27-31

The seven lean and ugly cows that came up after them are seven years, and the seven thin ears scorched by the east wind will be seven years of famine. It is as I have spoken to Pharaoh: God has shown to Pharaoh what He is about to do. Behold, seven years of great abundance are coming in all the land of Egypt; and after them seven years of famine will come, and all the abundance will be forgotten in the land of Egypt, and the famine will ravage the land. So the abundance will be unknown in the land because of that subsequent famine; for it will be very severe.