Manusmriti 12.120

12.120

khaṃ saṃniveśayet kheṣu ceṣṭanasparśane 'nilam
paktidṛṣṭyoḥ paraṃ tejaḥ snehe 'po gāṃ ca mūrtiṣu //

Let him meditate on the ether as identical with the cavities (of the body), on the wind as identical with the organs of motions and of touch, on the most excellent light as the same with his digestive organs and his sight, on water as the same with the (corporeal) fluids, on the earth as the same with the solid parts (of his body);