When sacred preaching floweth from the soul of the faithful, rivers of living water, as it were, run down from the bellies of believers. For what are the entrails of the belly but the inner part of the mind; i. e. a right intention, a holy desire, humility towards God, mercy toward man.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: super Ezech. Hom. x.