Go and stay in a monastery where there is a true teacher. Go deep into the mountains and valleys. Practice kinhin by clear waters and verdant mountains. Clear the mind by a stream or under a tree. Observe impermanence without fail and you will keep the mind that enters the Way.
From “Zazen Yojinki: Notes on What To Be Aware of in Zazen” by Keizan Jokin (from The Art of Just Sitting, Wisdom Publications, 2004)