Fourth Book of Kings (Author Compiled by Isaias and Jeremias from records of Nathan, Gad, Addo, Ahias, Jehu and others.)
20:3obsecro Domine memento quomodo ambulaverim coram te in veritate et in corde perfecto et quod placitum est coram te fecerim flevit itaque Ezechias fletu magno
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.