Verse 1.1.3

शौनको ह वै महाशालोऽङ्गिरसं विधिवदुपसन्नः पप्रच्छ ।
कस्मिन्नु भगवो विज्ञाते सर्वमिदं विज्ञातं भवतीति ॥ ३ ॥

śaunako ha vai mahāśālo'ṅgirasaṃ vidhivadupasannaḥ papraccha |
kasminnu bhagavo vijñāte sarvamidaṃ vijñātaṃ bhavatīti || 3 ||

3. Saunaka, a great grihasta, having duly approached Angiras, questioned him “What is that, O Bhagavan which being known, all this becomes known.” (3)

Shankara’s Commentary:

Com.—Saunaka, the male issue of Sunaka. Mahasalah means “the great house-holder”; Angiras, i.e., the disciple of Bharadvaja and his own preceptor; Vidhivat means ‘duly i.e., according to the sastras; Upasannah means ‘having approached Paprachha means ‘questioned from “the approaching duly” mentioned just after the connection between Saunaka and Angiras, it should be inferred that in resect of the manner of approaching, there was no established rule among the ancients, before him. The attribute “duly” might have been intended either to fix a limit, or to apply to all alike, on the analogy of a lamp placed amidst a house; for the rule about “the manner of approaching” is intended in the case of persons like us also. What did he say? “What is that? Oh Bhagavan, etc.” The particle ‘nu’ expresses doubt. Bhagavo means ‘O Bhagavan.’ “All this” means “everything knowable.” Vijnatam means ‘specially known or understood.’ [Oh Bhagavan what is that which being known everything knowable becomes well-known]. Saunaka having heard the saying of good men that “when one is known, he becomes the knower of all,” and being desirous of knowing that one in particular, asked in doubt “what is that, etc.”; or, having seen merely from a popular view, questioned. There are in the world varieties of pieces of gold, etc., which, though different are know n by people in the world by the knowledge of the unity of the substance (gold, etc.); similarly “Is there one cause of all the varieties in the world, which cause being known, all will be well-known?” It may be said that when the existence of the thing is not known, the question “what is that, etc.,” is not appropriate and the question in the form “is there, etc.,” would then he appropriate; if the existence is established, the question may well be “what is that, etc.,” as in the expression, “With whom shall it be deposited.” The objection is unsound; the question in this form is appropriate from fear of troubling by verbosity.