The Ishvara Gita is an ancient Hindu philosophical text from Kurma Purana. It follows the oldest Shaiva doctrine of the Vedic mahapashupata school with its scripture Atharvashiras Upanishad and predates the reformed Lakulish pashupata that appeared around 3000 BCE according to the chronology in Vayu Purana.
Pashupata means "the way to Pashupati" whereas Pashupati is defined as "Lord of all creatures" in Yajurveda. It is one of the names of God Shiva.
The text deals with topics such as Shiva Advaita (Shaiva nondualism) metaphysics, relations Shiva-brahman-Linga, yoga, recitations of om and of the hymn Shatarudriya from Yajurveda, [1] and others [2]
The Ishvara Gita consists of 11 chapters with over 768 verses which deals with topics such as worship of the Siva Lingam, Shiva Advaita metaphysics, Omni-Potence of the Śiva-Liṅga,[3] Bhakti, Significance of OM,[4] Theophany of Śiva (śiva-prādurbhāva-ākhya), forms of Shiva (Aṣṭa Mūrtis) and others
The Ishvara Gita contains many new themes that are not found in The Bhagavad Gita, such as worship of the Shiva Lingam and the idea of Śiva as the ultimate God. It also equalizes Shiva with brahman (absolute) as well as brahman with the linga. Shiva is in the form of a Linga which means a "mark" of the presence of God. Its philosophy is rooted in the Vedic Puranic tradition and does not have tantric connotations.
The Īśvara Gītā teaches the highest 8-fold yoga of brahman which bears a resemblance to the later 8-fold (ashtanga) yoga of Patanjali, and by itself is a textbook of the pashupata school of Shaivism. Several commentaries on this text are available in manuscript form, including one by Vijñānabhikṣu, a 16th-century Hindu polymath.
The Īśvara Gītā has been translated into English, French and Italian in stand-alone form, and into English as part of a complete translation of The Kurma Purana.