Genesis 30:4

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:

Thus saith the LORD, Behold, I will raise up evil against thee out of thine own house, and I will take thy wives before thine eyes, and give them unto thy neighbour, and he shall lie with thy wives in the sight of this sun.

Wherefore she said unto Abraham, Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac.

And his concubine, whose name was Reumah, she bare also Tebah, and Gaham, and Thahash, and Maachah.

And he put the handmaids and their children foremost, and Leah and her children after, and Rachel and Joseph hindermost.

But unto the sons of the concubines, which Abraham had, Abraham gave gifts, and sent them away from Isaac his son, while he yet lived, eastward, unto the east country.

Then again Abraham took a wife, and her name was Keturah.