Genesis 41:3

Very bank; to shew that the Nile had not inundated far, and that consequently a great famine would prevail, as the fertility of Egypt depends greatly on the overflowing of the Nile. "When the river rises 12 cubits, sterility pervades Egypt; when 13, famine is still felt. Fourteen cubits bring joy, 15 security, 16 delight. It has never yet been known to rise above 18 cubits." (Pliny, Natural History v. 9.) This successive depression of the waters was an effect of God's judgments, which no astrologers could foretel. (Tirinus)