The Upanishads, Part 2 (SBE15), by Max Müller, , at sacred-texts.com
Let him never shun food, that is the rule. Water is food, the light eats the food. The light rests on water, water rests on light. This is the food resting
on food 1. He who knows this food resting on food, rests exalted, becomes rich in food, and able to eat food (healthy), becomes great by offspring, cattle, and the splendour of his knowledge (of Brahman), great by fame.
66:1 Taught by Varuna, learnt by Bhrigu Vâruni.
66:2 Because, like food, it is inside the body.
66:3 The interdependence of food and breath. The object of this discussion is to show (see Saṅkara's commentary, p. 135) that the world owes its origin to there being an enjoyer (subject) and what is enjoyed (object), but that this distinction does not exist in the Self.
67:1 The interdependence of water and light.