Isan sent Tozan to Ungo Donjo, whom he asked, “Who can hear the non-sentient preach the Dharma?” Ungo answered, “The non-sentient can hear the non-sentient preach the Dharma.” Tozan asked, “Can you hear it?” Ungo replied, “If I could hear it, you would not be able to hear me preach the Dharma”. Tozan replied, “In that case I do not hear you preach the Dharma”. Ungo said, “If you still don’t hear me preach the Dharma, how much less can you hear the non-sentient preach the Dharma”. At this, Tozan had an insight. Inanimate phenomena teach the Dharma of inanimate phenomena; sentient beings teach the Dharma of sentient beings. The Dharma is not restricted to words and phrases, or even to sounds, it is also physiological and topological.