Bhagavad-Gîtâ

The Bhagavad Gita (Sanskrit  , "Song of God") is a Sanskrit text from the Bhishma Parva of the Mahabharata epic. Due to differences in recensions they may be numbered in the full text of the Mahabharata as chapters 6.25 – 42. or as chapters 6.23-40 According to the recension of the Gita commented on by Shankaracharya, the number of verses is 700, but there is evidence to show that some old manuscripts had 745 verses.
See more at Wikipedia.org...

Noun
1. (Hinduism) the sacred `song of God' composed about 200 BC and incorporated into the Mahabharata (a Sanskrit epic); contains a discussion between Krishna and the Indian hero Arjuna on human nature and the purpose of life
(synonym) Bhagavadgita, Gita
(hypernym) sacred text, sacred writing, religious writing, religious text
(part-holonym) Mahabharata, Mahabharatam, Mahabharatum
(classification) Hinduism, Hindooism

Bhagavad-Gita (Sanskrit) [from bhagavat illustrious, sacred, holy, lord (one of Krishna's titles) + gita song] The noble song, the Lord's song; a portion of the Bhagavad-Gita Parvan, one subsection of the Bhishma Parvan, itself one of the principle sections of the Mahabharata. The Bhagavad-Gita consists of a dialogue in which Krishna and Arjuna have a discussion upon the highest spiritual philosophy. Krishna in this instance is the inner instructor or monitor, the higher self, advising the human self or Arjuna.

The section of the Mahabharata in which Krishna reveals himself to Arjuna and in a long theological discussion describes the main components of karma yoga .