Explanation of the Diamond Sutra: Why Can a Sakṛdāgāmin of the Second Fruit Not Have the Thought "I Have Attained the Fruit of Sakṛdāgāmin"?

Original text of the Diamond Sutra, Chapter Nine: One Mark No-Mark: 须菩提。于意云何。斯陀含能作是念。我得斯陀含果不。须菩提言。不也。世尊。何以故。斯陀含名一往来。而实无往来。是名斯陀含。

Explanation: Subhūti, what do you think about this? Can a once-returner have such a thought, "I have attained the fruit of a once-returner"? Subhūti replied: A once-returner cannot have such a thought, World-Honored One. Why is this so? The once-returner is named "one who returns once," but in reality there is no such thing as coming or going; it is merely given the name "once-returner."

This passage carries the same meaning as the passage above on the first fruit. One who has truly attained the second fruit has an even emptier mind regarding the self of the five aggregates, with no notion of "I have attained the second fruit," much less clinging to "I have attained the second fruit," dwelling on it incessantly and proclaiming it everywhere for fear that others do not know, and becoming so angry as to ignore people if they do not believe it. Such deep clinging is clearly the emotional attachment of an ordinary being, having nothing to do with the first or second fruit.

A once-returner (Sakṛdāgāmin; Pali Sakadāgāmin) has afflictions lighter than those of ordinary beings and those of the first fruit. After death, he is reborn in the heavens once, returns to the human world once, and then attains the fourth fruit of an arhat, gaining liberation and exiting saṃsāra. Likewise, he does not regard the five aggregates and the eighteen realms as self; there is no concept of "I" in his mind, so he does not think that there is an "I" who has attained the fruit of a once-returner, nor that "I" can attain the fruit of a once-returner. A once-returner no longer regards the realms of the desire realm as truly existing dharmas, for these all belong to the realms of the six sense objects and are all illusory. Therefore, when he is reborn in the heavens, there is no place he goes to; when he returns to the human world, there is no place he returns from. There is no once-returner of the five aggregates who can come and go between humans and gods, so in reality there is no coming or going.

One who has attained the second fruit, after death in this life, will be reborn in a desire-realm heaven to continue cultivation. After death in the desire-realm heaven, he will return to the human world to continue cultivation. After attaining the fourth fruit of an arhat, upon death he enters nirvāṇa and is no longer reborn in the three realms to suffer, being liberated from the suffering of birth and death in the three realms. This is the single coming and going between heavens and the human world of the second-fruit once-returner. In substance, is there coming and going? There is no coming or going; the matter of coming and going is illusory and unreal. The five aggregates in the heavens and the five aggregates in the human world are all illusory and unreal, all false appearances, not the truth. Therefore, the once-returner also does not truly exist as a once-returner; the mark of the once-returner is also a non-mark, merely provisionally named "once-returner." We need not cling to a false name and mark, wasting our minds in vain. We should extinguish the mark of self and the mark of the once-returner, remaining unmoved no matter what attainment we achieve, without giving rise to clinging thoughts; otherwise we will fall into the cycle of birth and death, unable to escape.