Just as the one rain-water inside all herbs is transformed variously according to the numberless tastes, odours, properties and effects of the respective herbs, so is the inner self according to the characteristics of the various kinds of beings.  By virtue of it [the inner self] does the earth support all creatures, the clouds rain profusely, fire cooks and burns.  Hence is that the inner self of all.

One should clearly realise the self in all beings and all successive multitudes of created beings in the self.  He should, repeatedly and persistently, perceive all things as the self, having, for an example, the relation between water and waves.  There is only one Brahman without a second, as is declared by the Vedanta.  The many do not in any way exist. But he who sees this universe as manifold will not attain liberation.

* * *

It is thus clearly seen that the Lord of all the worlds is of the nature of pure consciousness, is the one Immovable that is knowledge itself, is all-pervading like ether, and is the inner spirit of all beings. It is also seen that all this universe is different from Brahman, is unreal by nature, and is a mere semblance,  One should, therefore, even now and here, give up all desires and remain forever fixed in the thought, “I am Brahman.”

excerpted from “The Century of Verses”
Sri Shankaracharya
tr. S. Venkataramanan