Genesis 9:20-23

20Now Noah, a man of the soil, proceeded1 to plant a vineyard. 21But when he drank some of its wine, he became drunk and uncovered himself inside his tent. 22And Ham, the father of Canaan, saw his father’s nakedness and told his two brothers outside.

23Then Shem and Japheth took a garment and placed it across their shoulders, and walking backward, they covered their father’s nakedness. Their faces were turned away so that they did not see their father’s nakedness.