Seclusion
Paṭisallāna Sutta  (SN 56:2)

“Take on the duty of seclusion, monks. A secluded monk discerns in line with what has come into being. And what does he discern in line with what has come into being?

“He discerns, ‘This is stress.’ He discerns, ‘This is the origination of stress.’ He discerns, ‘This is the cessation of stress.’ He discerns, ‘This is the path of practice leading to the cessation of stress.’

“Take on the duty of seclusion, monks. A secluded monk discerns in line with what has come into being.

“Therefore, monks, your duty is the contemplation, ‘This is stress … This is the origination of stress … This is the cessation of stress.’ Your duty is the contemplation, ‘This is the path of practice leading to the cessation of stress.’”