Why Can’t a Sakadagami Have the Thought "I Have Attained the Sakadagami Fruit"?

The Diamond Sutra Original Text: Subhuti, what do you think? Can a Sakadagami have the thought, 'I have attained the fruit of Sakadagami'? Subhuti said, No, World-Honored One. Why is that? Sakadagami means 'one who comes once more', yet there is actually no coming or going. It is merely named Sakadagami.

Literal Translation: The Buddha asked Subhuti: What is your view on this matter? Can a Sakadagami have such a thought, 'I have attained the fruit of Sakadagami'? Subhuti replied: A Sakadagami cannot have such a thought, World-Honored One. Why is that said? Sakadagami is named 'one who goes and comes once between heaven and the human realm', yet in reality, there is no such thing as going and coming. It is merely given the name Sakadagami.

Commentary: This passage shares the same meaning as the preceding section about the first fruit (Sotapanna). One who has truly attained the second fruit has an even greater emptiness regarding the mind of self based on the five aggregates. They do not hold the notion that 'I have attained the second fruit', much less cling to the idea of 'I have attained the second fruit', constantly dwelling on it, proclaiming it everywhere, and fearing that others do not know. If others do not believe, they might get angry and ignore people. Such deep clinging is clearly the emotional attachment of an ordinary being and has nothing to do with the first or second fruit.

One who has attained the second fruit, after the end of this present life, will be reborn in the desire realm heavens to continue their practice. After the end of that life in the desire realm heavens, they will return once more to the human realm to continue their practice. After attaining the fourth fruit of Arhatship, at the end of that life, they enter Nirvana, no longer reborn within the three realms to suffer, liberated from the suffering of birth and death within the three realms. This is the 'one coming and going between heaven and the human realm' of the second fruit Sakadagami. Is there any actual coming and going in essence? There is no coming and going. Matters of coming and going are all illusory and unreal. The five aggregates in heaven and the five aggregates in the human realm are both illusory and unreal; they are merely false appearances, not true reality. Therefore, the second fruit Sakadagami is not truly a Sakadagami. The appearance of Sakadagami is also non-appearance; it is merely provisionally named Sakadagami. We need not cling to a false name and appearance, wasting mental energy in vain. We should eliminate the notion of self and the notion of Sakadagami. Regardless of what achievements are attained, the mind remains unmoved, giving rise to no clinging. Otherwise, we will sink into the cycle of birth and death, unable to attain liberation.