। ॥ २६१ ॥
In plain words
One alone — and yet the cause of everything many. The very reason no other cause is ever needed. And beyond the whole idea of 'cause' and 'effect' itself. That is Brahman. And that is you. Hold it within.
Close to the Sanskrit
That which, being one alone, is the cause of the many; the reason for negating [the need for] any other cause; itself distinct from [both] effect and cause — that Brahman [is]: thou art That; contemplate [this] within yourself.