摩訶止觀 6.73

6.73

亦空亦有門者，智者見空及與不空。若言空者，則無常、樂、我、淨；若言不空，誰復受是常、樂、我、淨？如水、酒、酪、瓶，不可說空及以不空。是名亦空亦有門。

As for the gate of both emptiness and existence, the wise person sees emptiness as well as non-emptiness. If one says it is empty, then there is no permanence, bliss, self, or purity; if one says it is not empty, who would receive this permanence, bliss, self, and purity? Like a jar of water, wine, or curd, it cannot be said to be empty or not empty. This is called the gate of both emptiness and existence.