An aspect of Bitachon, trust in H'shem, is our belief that He will reward the righteous for their service and punish the wicked for their transgressions, in this world as well as in the World to Come.
pg 443
Nefesh Hachaim
From man's perspective, it is proper even required to think about and meditate on Torah thoughts in clean places while forbidden in others. From H'shem's perspective, He fills the world without discretion.
Gate Three, Chapter 6 pg 114/115