Entering the Flow, Forgetting the Object, and the Stream-Entry of the Srotāpanna

Question: In the Śūraṅgama Sūtra's perfect penetration through the ear faculty, what is the relationship among the phrase "entering the flow and forgetting the object," the later "domain of the aggregate of form," and what the Diamond Sutra says about the srotāpanna being called "one who has entered the flow" yet not entering form, sound, smell, taste, touch, or dharmas?

Answer: When Avalokiteśvara Bodhisattva cultivated the samādhi on the hearing nature through perfect penetration via the ear faculty, at the beginning, upon hearing sounds, he entered into the flow of sounds, knowing only the sounds, unaware of their source and of everything else. This kind of focused attention was the initial stage of meditative concentration (samādhi).

The Diamond Sutra says that the srotāpanna is called "one who has entered the flow" yet there is nothing entered; this flow refers to the six sense objects of form, sound, smell, taste, touch, and dharmas. Because the srotāpanna has realized that the five aggregates and eighteen realms are all empty, he no longer takes the six sense objects to be truly self or belonging to self; therefore, although he dwells amid the six sense objects, his mind does not attach to them.

The srotāpanna's entering the flow is a wisdom realm resulting from the eradication of the view of self (satkāya-dṛṣṭi), with wisdom as the primary element and meditative concentration as the auxiliary; Avalokiteśvara Bodhisattva's "entering the flow and forgetting the object" is primarily a state of meditative concentration, with wisdom as the auxiliary.

When one's practice enters the domain of the aggregate of form but one has not emerged from that domain, not passed through it, this is a state of meditative concentration.