Mahakratu Dasa : Prabhupada was on the vyasasana about to lecture, and there was a group of ten or twelve devotees sitting near him. I was sitting under a corner of the vyasasana. Hansadutta and Yasodanandana were also there. When Prabhupada started to speak in Hindi, a whole bunch of devotees got up to leave. Prabhupada stopped speaking. He looked at us and said in English, "This is for you as well. Where are you going? Stop. You should all stay here and listen." The devotees thought that they could walk away from Prabhupada's lecture since they didn't understand the language. But Prabhupada didn't like that at all. He wanted everybody to sit and listen because whether we understood it or not, it was purifying for us. Afterwards he said, "You devotees don't understand the potency of this preaching. It is what is going to purify your hearts. You'll become Krishna conscious by hearing, even if you don't understand, not by wandering around."
Reference:Memories-Anecdotes of a Modern-Day Saint by Siddhanta Dasa