It's a constant them on Russian TV. Putin himself said it to the Duma, in 2012 if I remember the book rightly. Links to audio won't help, unless you speak Russian. Do you? I can pull some URLs out of Keir Giles' book "Russia's War on Everybody". And of course there's the manifesto of "Putin's Brain", Aleksandr Dugin.
https://en.wikipedia.org/wiki/Foundations_of_Geopolitics
We'll leave aside Ivan Ilyin's little book "Our Tasks" for the moment. It's mentioned in two or three recent books I have handy, but I can't find an English translation. Ilyin goes beyond restoring the Soviet borders to creating a Russkiy Mir "extending from Lisbon to Vladivostok". It's reported to be required reading in every military school under Russian control.
I’m looking for a direct video link or a n article link to a credible source that quotes him.