"Red Sky at Night Sailors Delight; Red Sky in the Morning Sailors take Warning." This saying has very old roots. In the bible (Matthew 16:2-3), the following quote is attributed to Jesus: "When it is evening, ye say, fair weather: for the heaven is red. And in the morning, foul weather today for the heaven is red and lowering." There are also versions of this saying that refer to shepherds instead of sailors.