Bahiya asked the Buddha for the whole teaching in a few words, on the street, in a hurry. This four-line answer is said to have brought him to full awakening before he'd even walked away. Its method is subtraction: let the seen stay just seen, the heard just heard, before the mind adds a story about who's seeing it and what it means. Most of what ruins a morning is really the fifth thing you added to the first thing you noticed. Watch one ordinary moment today, a look, a tone of voice, and stop at what you actually saw, before the commentary starts.
In reference to the seen, there will be only the seen. In reference to the heard, only the heard. In reference to the sensed, only the sensed. In reference to the cognized, only the cognized.
Udana 1.10, the Bahiya Sutta (trans. Thanissaro Bhikkhu)