金剛經纂要刊定記 4.296

4.296

生因者，報化之身本來無有，萬行所致故名為生。故彌勒頌云：「於實為了因，亦為餘生因。」為經云：一切諸佛菩提法，皆從此經處。

As for the producing cause: the reward and transformation bodies fundamentally do not exist, and because they are brought about by the myriad practices they are called "produced." Therefore Maitreya's verse states: "For the real it is the revealing cause, / And also the producing cause for the rest." It is because the sūtra states: "All buddhas' bodhi teachings emerge from this sūtra."