A mendicant with good friends, companions, and associates can expect to be wise …

But then, a mendicant grounded on these five things should develop four further things. They should develop the perception of ugliness to give up greed, love to give up hate, mindfulness of breathing to cut off thinking, and perception of impermanence to uproot the conceit ‘I am’. When you perceive impermanence, the perception of not-self becomes stabilized. Perceiving not-self, you uproot the conceit ‘I am’ and attain extinguishment in this very life.”

Numbered Discourses 9.4 1. Awakening With Nandaka

At one time the Buddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery.

Now at that time Venerable Nandaka was educating, encouraging, firing up, and inspiring the mendicants in the assembly hall with a Dhamma talk. Then in the late afternoon, the Buddha came out of retreat and went to the assembly hall. He stood outside the door waiting for the talk to end. When he knew the talk had ended he cleared his throat and knocked on the door-panel. The mendicants opened the door for the Buddha, and he entered the assembly hall, where he sat down on the seat spread out.