All these worlds exists within That. There is nothing in these worlds which exists out of That. Even if one goes on ceaselessly with the motion of arrow shot off the bow-string, even if one goes on with the speed of the mind itself, one would not still get at the end of that which is the cause of all this. There is nothing grosser than that.
सर्वेऽन्तःस्था इमे लोका बाह्ममेषां न किंचन। यद्यजस्रं समागच्छेद् यथा बाणो गुणच्युतः॥ नैवान्तं कारणस्येयाद् यद्यपि स्यान्मनोजवः। तस्मात् सूक्ष्मात् सूक्ष्मतरं नास्ति स्थूलतरं ततः॥