妙法蓮華經玄贊 4.202

4.202

贊曰：此稱佛作佛，且舉一稱尚得作佛，何況多稱？如《藥王藥上經》云「我常稱五十三佛名故，今得作佛」，即其事也。

The Eulogy says: This is attaining buddhahood through reciting the Buddha's name. It provisionally cites a single recitation still being able to attain buddhahood, how much more so many recitations? As the Sūtra of Bhaiṣajyarāja and Bhaiṣajyasamudgata says: 'Because I constantly recited the names of the fifty-three buddhas, I now attain buddhahood,' which refers to this very matter.