Su Dongpo and Fo Yin were good friends who enjoyed teasing each other. One day, while meditating together, Fo Yin praised Su Dongpo for looking like a noble buddha. When Su Dongpo asked how he looked, Fo Yin simply smiled without responding after Su Dongpo said he looked like cow dung. Later, Su Dongpo's sister pointed out that while Fo Yin saw with a buddha's heart, Su Dongpo saw with the heart of dung, showing his perspective was inferior. The reflection is that one sees the world according to one's inner state of mind.