ואני זאת בריתי אותם אמר השם רוחי אשר עליך ודברי אשר שמתי בפיך לא ימושו מפיך ומפי זרעך ומפי זרע זרעך אמר השם מעתה ועד עולם - "As for Me this is my covenant with them", says Hashem, "My spirit which is upon you and My words that I have placed in your mouth, shall not move from your mouth and from the mouth of your seed and from the mouth of your seeds seed" said Hashem. [Yeshaya 59/21 and part of the daily ובא לציון].
Rashi explains that this means that even in the galus, Torah will not be forgotten.
This connects to the bracha we say every morning on learning Torah - ונהיה אנחנו וצאצאינו וצאצאי עמך בית ישראל כולנו יודעי שמך. We and our children and the children of your nation the House of Israel should all know Your name.
In what merit will our children continue the chain and keep learning Torah? Shmiras HaBris [i.e. sexual purity]. This is alluded to in the word אותם which is comprised of the words אות תם - "the sign of completion" which is the Bris. If we guard our Bris [בריתי אותם] then "My spirit which is upon you and My words that I have placed in your mouth, shall not move from your mouth and from the mouth of your seed and from the mouth of your seeds seed".
[Tiferes Shlomo on Birkas Hatorah]
לזכות שמואל אלכסנדר בן נעכא גיטל