The practice of chanting the Odaimoku was not intended to completely replace either the study of the sutra or the reading of the sutra, though it could replace the practice of reciting each of the twenty-eight chapters as a practice. In one of his letters to a believer he said it was permissible to replace the practice of reciting a chapter a day for twenty-eight days with the single practice of chanting the Odaimoku. It is important to note that he did not say it was wrong to chant the twenty-eight chapters, in fact in Nichiren Shu temples the entire Lotus Sutra is chanted on various cycles of twenty-eight days or in some cases fewer.