Deuteronomy 27:20

And it came to pass, when Israel dwelt in that land, that Reuben went and lay with Bilhah his father's concubine: and Israel heard it. Now the sons of Jacob were twelve:

Unstable as water, thou shalt not excel; because thou wentest up to thy father's bed; then defiledst thou it: he went up to my couch.

The nakedness of thy father's wife shalt thou not uncover: it is thy father's nakedness.

And the man that lieth with his father's wife hath uncovered his father's nakedness: both of them shall surely be put to death; their blood shall be upon them.

A man shall not take his father's wife, nor discover his father's skirt.

So they spread Absalom a tent upon the top of the house; and Absalom went in unto his father's concubines in the sight of all Israel.

Now the sons of Reuben the firstborn of Israel, (for he was the firstborn; but forasmuch as he defiled his father's bed, his birthright was given unto the sons of Joseph the son of Israel: and the genealogy is not to be reckoned after the birthright.

In thee have they discovered their fathers' nakedness: in thee have they humbled her that was set apart for pollution.