Yeshayah 59:21

As for Me, this is My Brit (Covenant) with them, saith HASHEM; My Ruach that is upon thee, and My words which I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy zera, nor out of the mouth of the zera of thy zera, saith HASHEM, from henceforth and ad olam (forever).