karoty edhamsi bhasmasat
tatha mad-visaya bhaktir
yatha—as; agnih—a fire; su-samrddha-arcih—having a full flame; karoti—makes; edhamsi—fuel; bhasmasat—into ashes; tatha—similarly; mat-visaya bhaktih—devotional service in relation to Me; uddhava—O Uddhava; enamsi—all kinds of sinful activity; krtsnasah—totally.
" 'As all fuel is burned to ashes by a full-fledged fire, all sinful activities are totally erased when one engages in devotional service to Me.'
This verse is from Srimad-Bhagavatam (11.14.19).
Link to this page: https://prabhupadabooks.com/cc/madhya/24/61