“There are neither one nor many Buddhas. You can’t say there is only one, as there are limitless Buddhas, yet you can’t say there are many, as their essence is a single ground- emptiness and compassion abiding like space.
Thus, do not grasp at singularity or multiplicity. Whatever appear are empty of self nature, like a rainbow in the sky. They lack inherent existence, as they are compounds and thus impermanent.
The nature of mind of all beings always remains like space; it is uncompounded. While their bodies appear diversely, the mind of all beings has the same essence.
There is only one such thing called “mind,” just as there is only one such thing called “water,” although water manifests in different ways–as oceans, rivers, rain, drops, etc.
If everyone were to practice OM AH HUNG, their mindfulness would have the same essence without the slightest difference in quality or size.”
~ Garchen Rinpoche