大乘入道次第開決 1.171

1.171

生由漸染堪聞等者。如深好色漸染方成。究竟大乘漸聞始悟。故初說有次乃談空。後時方說非空非有。契會中道乃名圓宗。

Regarding 'Sentient beings become capable of hearing through gradual dyeing,' etc.: Just as a deep, fine color is accomplished only through gradual dyeing, so too the ultimate Mahāyāna is realized only when gradually heard. Therefore, he first spoke of existence, then discussed emptiness, and only later spoke of neither empty nor existent; tallying with the Middle Way, it is named the consummate teaching.