Genesis 9:22
20 Noah, a man of the soil, began to plant a vineyard. 21 When he drank some of the wine, he got drunk and uncovered himself inside his tent. 22 Ham, the father of Canaan, saw his father’s nakedness and told his two brothers who were outside. 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. 24 When Noah awoke from his drunken stupor he learned what his youngest son had done to him.
Leviticus 18:7
5 So you must keep my statutes and my regulations; anyone who does so will live by keeping them. I am the Lord. 6 “‘No man is to approach any close relative to have sexual relations with her. I am the Lord. 7 You must not expose your father’s nakedness by having sexual relations with your mother. She is your mother; you must not have sexual relations with her. 8 You must not have sexual relations with your father’s wife; she is your father’s nakedness. 9 You must not have sexual relations with your sister, whether she is your father’s daughter or your mother’s daughter, whether she is born in the same household or born outside it; you must not have sexual relations with either of them.
Notes and References
"... We begin with the idiomatic meaning of the phrase 'to see the father's nakedness' (verse 22). Proponents of the theory of paternal incest are correct to equate 'to uncover nakedness' via Leviticus 20:17, understanding both as euphemisms for sexual intercourse. However, one may take this valid insight one step further by recognizing that in all the relevant texts, it is associated with heterosexual activity, and 'the nakedness of the father' actually refers to the mother's nakedness. For example, in Leviticus 18:7-8, the 'nakedness of your father' is defined as 'the nakedness of your mother' ... Likewise, Leviticus 18:14, 16; 20:11, 30, 21 all describe a woman's nakedness as the nakedness of her husband. The same logic is at work in Deuteronomy 23:1 and 27:20, which describe intercourse with one's father's wife as 'uncovering the fathers skirt' ..."
Bergsma, John S. and Scott W. Hahn Noah's Nakedness and the Curse on Canaan (pp. 25-40) Journal of Biblical Literature 124/1, 2005