Vishnupurana 3.7.3

3.7.3

sthūlaiḥ sūkṣmais tathā sūkṣmasūkṣmāsūkṣmataraiḥ smṛtā /
sthūlātsthūlataraiś caiva sarvaṃ prāṇibhir āvṛtam //

MAITREYA.--You have indeed related to me, most excellent Brahman, all that I asked of you; but I am desirous to hear one thing which you have not touched on. This universe, composed of seven zones, with its seven subterrestrial regions, and seven spheres--this whole egg of Brahmá.--is every where swarming with living creatures, large or small, with smaller and smallest, and larger and largest; so that there is not the eighth part of an inch in which they do not abound. Now all these are captives in the chains of acts, and at the end of their existence become slaves to the power of Yama, by whom they are sentenced to painful punishments. Released from these inflictions, they are again born in the condition of gods, men, or the like: and thus living beings, as the Śástras apprise us, perpetually revolve. Now the question I have to ask, and which you are so well able to answer, is, by what acts men may free themselves from subjection to Yama?