שלום וברכה!
[תשכ"ב?]
נאום ברבים - מטרתו השפעה על השומעים, וכיון שהם שבעי רצון - הושגה המטרה. ובאם הנואם איננו שבע רצון - מעלה נוספת - שהצלחתו לא הביאתו לגאוה וכיו"ב.
נדפסה בלקו"ש חכ"ג ע' 547.
Shalom u'Vrachah!
A public speech—its purpose is to influence the listeners, and since they are satisfied, the goal has been achieved. And if the speaker himself is not satisfied—this is an additional merit—that his success did not lead him to pride or similar traits.
Summary
The Rebbe teaches that true success in public speaking lies in positively impacting others. Remaining humble even after achieving this influence is an even greater virtue.