। ॥ ३८५ ॥
In plain words
Let the three sheaths come together, and what they form is the subtle body of the ātman. It is the pointer: the ātman is so fine that it lies hidden, and this is what makes it known.
Close to the Sanskrit
The three sheaths, having combined — this would be the subtle body of the Self; because of its being the indicator of the Self, which lies hidden by reason of its extreme subtlety.