The Longer Discourse at Assapura 16.3

16.3

Seyyathāpi, bhikkhave, udakarahado ubbhidodako. Tassa nevassa puratthimāya disāya udakassa āyamukhaṃ, na pacchimāya disāya udakassa āyamukhaṃ, na uttarāya disāya udakassa āyamukhaṃ, na dakkhiṇāya disāya udakassa āyamukhaṃ, devo ca na kālena kālaṃ sammādhāraṃ anuppaveccheyya. Atha kho tamhāva udakarahadā sītā vāridhārā ubbhijjitvā tameva udakarahadaṃ sītena vārinā abhisandeyya parisandeyya paripūreyya paripphareyya, nāssa kiñci sabbāvato udakarahadassa sītena vārinā apphuṭaṃ assa.

It’s like a deep lake fed by spring water. There’s no inlet to the east, west, north, or south, and the heavens would not properly bestow showers from time to time. But the stream of cool water welling up in the lake drenches, steeps, fills, and spreads throughout the lake. There’s no part of the lake that’s not spread through with cool water.