This is a brief note on my ongoing research on the cycle of texts featuring the three Sakyan friends, Anuruddha, Nandiya, and Kimbila. It’s mainly found in MN 32 and MN 128, with part in the Vinaya (pli-tv-kd10:4.2.1) and a reference in the Theragatha (Thag 2.18), which is where we find the term “Sakyan friends” (sakyaputtā sahāyakā).
The story is well known and I won’t repeat it here. Have a read!
Some years ago, when first translating this, I made a passing note to myself to the effect that the narrative structure, especially of MN 31, and to a lesser degree MN 128, was reminiscent of Bṛhadāraṇyaka Upaniṣad 4.3. Do yourself a favor:
Note that this includes the lengthy commentary by Śaṅkāra, so skip that when just reading the text. But we’ll return to it.
In this rather charming story, King Janaka asks Yājñavalkya, “What is a person’s light?” Yājñavalkya, apparently feeling a bit emo on the day, tries to avoid answering directly, giving the most basic answer he can and only moving towards more profound answers when repeatedly prompted.
This is the same as MN 31, where Anuruddha gives the most basic answer to the Buddha when asked about meditation, then only gradually reveals the true depths of his practice.
Interesting parallel, but I didn’t think too much of it.
Returning years later to the sutta, I noticed a term that had a distinctly Upanishadic ring to it: attakāmarūpa.
Santettha tayo kulaputtā attakāmarūpā viharanti.
There are three gentlemen staying here who are attakāmarūpā.
This is explained by the commentary as one whose nature (sabhāva, glossing rūpa) is to desire (kāma) their own welfare (attano hitaṁ). Translators have generally followed the commentary, with the notable exception of IB Horner, who translated “desiring Self”. Most translators ignore the rūpa part, except Thanissaro who renders it “seemingly”, as if it were ranch.
The commentarial approach, which normalizes the term in an acceptably Buddhist way, has never been entirely satisfactory, as it renders a very particular and unique phrase with something generic like “seeking their own good”.
There are three gentlemen staying here who are seeking their own good.
Anyway I checked the early Sanskrit texts and it turns out there is a close analogy in the Upanishads (Bṛhadāraṇyaka Upaniṣad 4.3.21).
ātmakāmam āptakāmam akāmaṁ rūpaṁ
And similarly:
niṣkāma āptakāma ātmakāmo
The exact sense of this phrase is a little tricky, and must be read in context. The two prefixes ātma- and āpta- are clearly euphonious and their order is reversed in variants.
But the basic sense is something like: “having attained their only desire, the Self, their nature (or form) is without desire”. It refers to a state of realization of oneness with Brahma in deep sleep or at death.
The use of rūpa here confirms the gloss sabhāva in the commentary (note that sabhāva itself is elsewhere glossed sarūpa). It indicates the “true nature” of the person.
Thus there seems no doubt the true sense of the Pali phrase is:
There are three gentlemen staying here whose nature is to desire only the self.
If it be objected that this is not a Buddhist sentiment, then the answer is: why should it be? The term occurs only once, spoken by an anonymous park keeper—not a monastery attendant, just the gardener of a public park—who does not recognize the Buddha.
There’s no reason to think he was Buddhist, and every reason to think he was a Vedist, describing the contemplatives in the terms he learned from his own contemplative tradition. It still happens today that Buddhist monastics are looked after, supported, and respected by Hindus, who nonetheless think of them in the terms of their own religion. In fact, I have to hurry up and finish writing so I can go on pindapata to me local Hindu restaurants, where they feed me every day! 
This linguistic usage is highly specific and pins this exchange down to this passage in the Bṛhadāraṇyaka Upaniṣad.
Which, as it turns out, is the same chapter as the one on the search for the light! So for me, it took several years between making a note on a passing narrative resemblance, to then independently identifying a much more specific linguistic commonality.
The theme of BU 4.3, however, is quite different, as it concerns the search for the inner light.
Hang on.
Wait a minute.
MN 128 is all about that. It goes step by step through “seeing lights and vision of forms”. A different word for “light” (obhāsa vs. jyoti), and obviously a different metaphysical context, but the basic idea is the same: how do we find the light inside ourselves?
One is a coincidence, two a hint, three … is pretty much as good as it gets.
So these suttas share with BU 4.3:
- narrative structure (reluctance and questioning)
- unique terminology
- theme (finding the inner light)
That’s it, I’m calling it: the sutta cycle of the three Sakyan friends draws on Bṛhadāraṇyaka Upaniṣad 4.3.
There might well be other details, I’m still looking into it.
But there is one curious wrinkle to this finding. Check the commentary to 4.3.7. Śaṅkāra has a long discussion of this line, and he includes a lengthy series of objections and rebuttals from a Buddhist point of view. I’m no expert on Śaṅkāra, but I believe this is quite unusual. In fact, I don’t think he discusses Buddhism in detail anywhere else in this commentary, although, to be sure, he does do so in other places.
I don’t know what to make of this. Maybe nothing. But it does seem odd that when commenting on a passage that sparked a Buddhist response, he felt the need to respond to Buddhists. I don’t know that Śaṅkāra even knew the suttas. He usually talks about the later schools. But could there be some memory somehow of the connection?
So much for that “self!”