From the Vinaya Atthakathā:
- channamativassatī ti āpattiṃ āpajjitvā paṭicchādento aññaṃ navaṃ āpattiṃ āpajjati idametaṃ sandhāya vuttaṃ.
“It rains hard on the covered” — this was stated in connection with one who, having committed an offence, concealing it commits another new offence
vivaṭaṃ nātivassatī ti āpattiṃ āpajjitvā vivaranto aññaṃ nāpajjati idametaṃ sandhāya vuttaṃ.
“It rains not hard on the open” — this was stated in connection with one who, having committed an offence, disclosing it does not commit any further offence.
Relating this to Horner’s translation: when a raindrop falls on, say, a roof or a lid, it makes a noise. It then bounces off, lands on the ground and makes a further noise. But if the raindrop falls on uncovered soil, grass, etc. then it is absorbed and so only gets to make one noise.
Relating it to Ajahn Thanissaro’s translation: the raindrops accumulate when they land on a covering but don’t accumulate if they fall on the ground.
Of the two I find Horner’s the likelier. With “It rains hard...” she plausibly treats
ativassati as an impersonal verb (as the verb “to rain” usually is in Indo-European languages). But with “Rain soddens...” Thanissaro invents a subject where the Pali has none and then has this subject perform an action (“to sodden”), despite there being no grounds for supposing that “soddening” lies within
ativassati’s semantic range.