What is the classical understanding of why people in the Buddha’s time were able to enlighten just by hearing a sutta when texts like the Visuddhimagga, and many suttas themselves describe a long process of meditation and development of jhanas and insight etc. to be needed to achieve similar stages?
Classically speaking from what I have heard several times in the Pa-auk world is that they had previously made a determination to follow the Buddha and attain enlightenment in his presence. In these cases you mention, specifically to do so very quickly.
They had attained saṅkhāraupekkhañāṇa many times and refrained from attainments.
It is similar to a Bodhisatta vow in terms of cooking time, but not nearly as long as a real sammaSamBuddho.
I’m not sure about the times, but it is a long long long time, if you make a determination like that.
You have to understand how special and rare it is to be born human during the time of a Buddha let alone be taught in His presence to fully appreciate this. These are not normal beings who just happened to be around during the time of the Buddha. It might be hard to digest, but think of the Buddha who did so in a single night, without listening to a dhammatalk, or stanza.
Even Ven Devadatta is special and his days roaming (or suffering) in saṃsāra are actually numbered. He might escape saṃsāra quicker than most Buddhist in the world today. Why? It was predicted at the time of his death that he would become a Paccekka Buddha. Therefore his time might be limited to 2 asankhaya. A very long time, but not long at all.
How interesting. Yes if they made an attidhana as such it certainly makes sense. I also heard (I think from thanissaro) that jhana was the leisure of people in India at the time so they’re minds were already well developed. Many of his listeners would “meditate” while listening to a sutta and become enlightened that way.
I always make aditthana saying that “By the power of such merits done now, let me attain Sotapannahood in this very lifetime. Let me fully abandon Sakkaya Ditthi, Vicikiccha and Silabbata paramasa.”
And I think it is a mental motivation too.