Tripura Rahasya is an important text in Hinduism that
explores the Advaita philosophy. Below is the link to Tripura Rahasya in
English with meaning. The text is in pdf format and is free for download.
Hindu Shiva originally taught the Highest Truth through
Tripura Rahasya to Vishnu, who in turn taught Brahma in the celestial regions.
Later Vishnu incarnated on Earth as Sri Dattatreya, the Lord of the Avadhutas
(the naked sages), and taught it to Parasurama.
Link – Tripura Rahasya in pdf