Nichiren Daishonin states in “Reply to Shijo Kingo
(Shijo kingo dono-gohenji)”:
The Lotus Sutra states: “If, after my passing, there are good men and good women, and one among them secretly preaches the entire Lotus Sutra or a phrase of it to even one other person, then you should know that this individual, indeed, is an envoy of the Tathagata. As the Tathagata’s envoy, he carries out compassionate action in his stead.” A person who recites even a character or a phrase of the Lotus Sutra and also preaches it to others is an envoy of Lord Shakyamuni.
法华经云“若是善男子 善女人 我灭度后 能窃为一人说法华经 乃至一句 当知是人 则如来使 如来所遣 行如来事”等云云。一字一句唱法华经，又向人说，即为教主释尊之使也。