Dogen:

Those who know a speck of dust know the entire universe; those who penetrate a single dharma penetrate all dharmas. If you do not pentrate all dharmas, you do not penetrate a dharma. When you understand the meaning of penetration (tsu) and thereby penetrate thoroughly, you discern all dharmas as well as a single dharma. For this reason, while you study a speck of dust, you study the whole universe without fail.

(Eighei Dogen: Mystical Realist, Hee-Jin Kim)

Thusness:

"When one says mind or basis or clarity or presence, it is only conventional expression. If we mistaken there is anything to grasp or anything beyond or ineffable, it is immediately mistaken. However if we just stop there it becomes nihilistic. Because the purpose is to allow one to clearly and fully realize, feel and taste the moment to moment of manifestation. To clearly see and understand the nature of what is felt, seen, taste, heard and thought. It is not only no seer, but in the seen just the seen. However in the seen just the seen can be seen as a form of focus shamatha concentration. Therefore I always say it is the natural state."