When we worship gods or Buddhas, we begin with the phrase of “namu.” Namu is an Indian word that has come to mean “offering of life to Buddhas and gods” in China and Japan. Our social standing is determined in part by possessing a spouse and children, retainers, fiefs, and gold and silver, though some people do not have these. Regardless of whether we possess these or not, no one possesses treasure more precious than life. Accordingly, sages and wise men in the past have donated their lives to the Buddhas in order to attain Buddhahood.

That is to say, Young Ascetic in the Snow Mountains offered his own body to a demon in order to learn a holy teaching consisting of eight Chinese characters. Medicine King Bodhisattva burned his own elbow and offered it to the Lotus Sūtra as a light. In Japan, Prince Shōtoku peeled the skin of his own hand to write the Lotus Sūtra on it, and Emperor Tenchi burned his third finger as an offering to Śākyamuni Buddha. These are deeds of sages and wise men, which are impossible for us ordinary people to emulate.

Nevertheless, ordinary people can become Buddhas by fully understanding the meaning of the word of “kokorozashi (intention)” and practicing it. What is the intention? When we consider this in detail, it refers to the doctrine of spiritual contemplation. What does the doctrine of spiritual contemplation mean? It means the way of practicing the teaching of the Buddha according to the intent of the Buddha, not necessarily according to what is literally said in the sūtra. For example, if a man donates his only set of clothes, which he wears for the cause of the Lotus Sūtra, this is the same as peeling his own skin for the sake of the Dharma. Suppose there is a man during the time of a famine who offers to the Buddha the only food he has to stay alive for a day. This is the same as offering his life to the Buddha.

These offerings are as meritorious as the offering of an elbow by Medicine King Bodhisattva or the offering by Young Ascetic in the Snow Mountains of his own body to a demon. Therefore, we can say that the self-sacrificial offerings of sages are phenomenal whereas the offerings of ordinary people according to the intent of the Buddha are noumenal. The doctrine of offering, one of the six practices for bodhisattvas to attain enlightenment, preached in the Great Concentration and Insight, part seven, refers to this noumenal offering, i.e. the practice of offering according to the intent of the Buddha.

Jiri Kyuō Gosho, Phenomenal Offering and Noumenal Offering, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 98