Contains selections from the Rigveda, Five Upanishads, and the Bhagavadgita.
About the Rigveda (from Wikipedia):
The Rigveda or Rig Veda is an ancient Indian collection of Vedic Sanskrit hymns. It is one of the four sacred canonical texts (śruti) of Hinduism known as the Vedas.
The Rigveda is the oldest known Vedic Sanskrit text. The Rigveda Samhita is the core text, and is a collection of 10 books (maṇḍalas) with 1,028 hymns (sūktas) in about 10,600 verses (called ṛc, eponymous of the name Rigveda). In the eight books – Books 2 through 9 – that were composed the earliest, the hymns predominantly discuss cosmology and praise deities. The more recent books (Books 1 and 10) in part also deal with philosophical or speculative questions, virtues such as dāna (charity) in society, questions about the origin of the universe and the nature of the divine, and other metaphysical issues in their hymns.
About the Upanishads (from Wikipedia):
The Upanishads are late Vedic Sanskrit texts of Hindu philosophy which form the foundations of Hinduism. They are the most recent part of the Vedas, the oldest scriptures of Hinduism, and deal with meditation, philosophy, and ontological knowledge; other parts of the Vedas deal with mantras, benedictions, rituals, ceremonies, and sacrifices. Among the most important literature in the history of Indian religions and culture, the Upanishads played an important role in the development of spiritual ideas in ancient India, marking a transition from Vedic ritualism to new ideas and institutions. Of all Vedic literature, the Upanishads alone are widely known, and their central ideas are at the spiritual core of Hinduism.
About the Bhagavadgita (from Wikipedia):
The Gita is set in a narrative framework of a dialogue between Pandava prince Arjuna and his guide and charioteer Krishna, an avatar of Lord Vishnu. At the start of the Dharma Yuddha (righteous war) between Pandavas and Kauravas, Arjuna is filled with moral dilemma and despair about the violence and death the war will cause in the battle against his own kin. He wonders if he should renounce and seeks Krishna’s counsel, whose answers and discourse constitute the Bhagavad Gita. Krishna counsels Arjuna to “fulfill his Kshatriya (warrior) duty to uphold the Dharma” through “selfless action”. The Krishna–Arjuna dialogues cover a broad range of spiritual topics, touching upon ethical dilemmas and philosophical issues that go far beyond the war Arjuna faces.
The Bhagavad Gita is the best known and most famous of Hindu texts,[13] with a unique pan-Hindu influence.The Gita’s call for selfless action inspired many leaders of the Indian independence movement including Bal Gangadhar Tilak and Mahatma Gandhi; the latter referred to it as his “spiritual dictionary”.