Fourth Book of Kings (Author Compiled by Isaias and Jeremias from records of Nathan, Gad, Addo, Ahias, Jehu and others.)
18:27responditque eis Rabsaces numquid ad dominum tuum et ad te misit me dominus meus ut loquerer sermones hos et non ad viros qui sedent super murum ut comedant stercora sua et bibant urinam suam vobiscum
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.