section 145 · 111 of 248
The Code of Hammurabi
English, translated by C. H. W. Johns — Johns, The Oldest Code of Laws in the World, Edinburgh, 1903
If a man has espoused a votary, and she has not granted him children and he has set his face to take a concubine, that man shall take a concubine, he shall cause her to enter into his house. That concubine he shall not put on an equality with the wife.