What should be My Preaching Verse?

Niranjana Dasa: In Scotland, he wrote that. I said, "What should be my preaching verse?" "So you are asking your preaching verse. The first thing you yourself follow four principles. Do not let a single day without chanting 16 rounds. Wear tilaka and kanti, that itself is a strong behavior. People will inquire about Krishna there; you can tell them."

I think each and every one of his letter he gave some instructions.