स यदवोच प्राण प्रपद्य इति प्राणो वाइद सर्व भूत यदिद किञ्च तमेव तत्प्रापत्सि ॥ ४ ॥
In plain words
That statement, 'I take refuge in prana'—prana indeed is this entire created universe, and everything that exists. By seeking prana, you attain all that.
Close to the Sanskrit
That which he spoke, 'I take refuge in prana' — prana indeed is all this created world, whatever else exists; you will attain that very thing.