In plain words
Dear young men! This is a most important time of life. The life of a human being may be likened to a mansion of four storeys. Those four storeys are none other than the āśramas of brahmacarya, gṛhastha, vānaprastha and sannyāsa. Today you are laying the foundation of such a mansion. The firmer this foundation is, the more secure the mansion of your life will be.
Every human being has four kinds of birth. The first is being born from the mother's womb. That is the natural birth. The second is receiving the upadeśa of the Gāyatrī mantra; through it a man becomes a dvija. After that, through study of the Vedas, he becomes a vipra. Once he has recognised the principle of Brahman, he becomes a brāhmaṇa. One must become a brāhmaṇa not merely by birth but by karma. Only one who has recognised the principle of Brahman has the right to call himself a brāhmaṇa.
All the deities live in man himself. The gross food we eat is the form of Brahmā. The subtle form of food is itself the form of Viṣṇu; its subtlest form is itself the form of Īśvara. That is why it is said, “Annaṃ Brahma raso Viṣṇuḥ.” Gross food gives strength to the body; subtle food gives strength to the mind; the subtlest food brings purity of speech. So the root and basis of strength of body, strength of mind and purity of speech is food itself.
Gāyatrī, Sāvitrī, Sarasvatī
Gāyatrī is the embodiment of all the deities, the embodiment of all mantras. “Gāyatrīṃ chandasāṃ mātā.” This Gāyatrī is the mother of the Vedas. The Gāyatrī mantra is no ordinary thing. If you repeat the Gāyatrī mantra, that is enough; you need not repeat any other mantra. Gāyatrī has three names. The first is Gāyatrī, the second Sāvitrī, the third Sarasvatī. “Gāyantaṃ trāyate iti Gāyatrī”: she who protects those who remember her is Gāyatrī. Gāyatrī is the ruler of the senses; Sāvitrī is the ruler of the life-breaths.