In plain words
Food is the support of this prāṇa. The sun is the support of food. By the light of the sun it turns water into vapour, shapes it into clouds, then pours down as rain, and through that rain makes the whole world green with crops. It ripens the harvests. It provides food. So the whole world rests on these three: prāṇa, food and the sun. That itself is Sat-i-em = Satya.
When we wish to attain God, the very form of Satya, we must follow the principle of Prema
How can we recognise this Satya? Satya: this is one word. It is Sat-i-ya = Satya. Besides this, sa-ta-ya = Satya. But when we turn sa-ta-ya around, it becomes ya-ta-sa. When one practises tapas, called ‘ta’, through ‘ya’, the marks of yama, niyama and the rest, God reveals Himself as ‘sa’, the very form of Satya. When by the paths of yama, niyama and the rest one practises tapas, the letter ta, the One whose form is Satya, the letter sa, reveals Himself. This is what Vedānta has gone on teaching as the aṣṭāṅga yoga. Yama, niyama, āsana, prāṇāyāma, pratyāhāra, dhāraṇa, dhyāna, samādhi. All these yogas belong to the bodily, the natural, the physical world; for God they are nothing, except the one yoga of Prema. Yoga means joining. As for this joining, apart from the one principle of Prema, no other path has any chance at all of reaching it. So when we wish to attain the Divinity called Satya, we must follow the principle of Prema. Every man needs certain values very much. Humanness without values has no place in this. What is the value of fire? It has the power to burn. If the power to burn itself is not there, it is not fire; it becomes charcoal. What is the value of sugar? Only when it is sweet is it sugar. Without that sweetness it becomes dirt, not sugar. What is the quality of snow? Coolness. Only when it has that coolness is it snow; if it is warm, it is not called snow. In the same way every thing has a power of its own. That power itself is the value of that thing's form.