I have heard an argument that Bāhiya attained arahantship without jhāna. This rests on the report from Ud 1.10, which claims that he attained arahantship just by listening to a short teaching.
I find it highly unlikely that that happened. i also notice that there are two other suttas mentioning a Bāhiya, SN 47.15 : Bahiya; and SN 35.89 : Bahiya. It has been proposed that these both represent two Bāhiya-named people neither of whom are the same as the one above.
I see that of these 3 suttas, only SN 47.15 has a known parallel. (If anyone can shed any light (or a translation!) about the parallel I would be grateful!) I rather doubt that they are different people. All 3 suttas seem very similar, in that they have the Buddha giving a very brief teaching to Bāhiya, and then it concludes with him becoming an arahant. That seems like too much of a coincidence, so I can’t help considering that they may all come from a common source.
But while the SN stories have him going off after the teaching, “dwelling alone, withdrawn, diligent, ardent, and resolute” which implies that he was quite possibly practicing jhāna; the Ud version has him attaining Arahantship without spending any time doing any practices after receiving the teaching. And this leads me to doubt the authenticity of the Ud version.
I also doubt the authenticity of the Ud version because the suttapitaka as a whole seems to teach that becoming an arahant is impossible without jhāna.
Anyone have any views on this? Or any other reasons why the Ud story may be false, or of the Ud’s Bāhiya practicing jhāna? (From early sources).