Genesis 9:21-23
9:21 When he drank some of the wine, he got drunk and uncovered himself inside his tent.
9:22 Ham, the father of Canaan, saw his father’s nakedness and told his two brothers who were outside.
9:23 Shem and Japheth took the garment and placed it on their shoulders. Then they walked in backwards and covered up their father’s nakedness. Their faces were turned the other way so they did not see their father’s nakedness.