Genesis 9:20-25
Noah farmed the land and was the first to plant a vineyard. One day he got drunk and was lying naked in his tent. Ham entered the tent and saw him naked, then went back outside and told his brothers. Shem and Japheth put a robe over their shoulders and walked backwards into the tent. Without looking at their father, they placed it over his body.

When Noah woke up and learned what his youngest son had done, he said, "I now put a curse on Canaan! He will be the lowest slave of his brothers."