The Lalitha Sahasranamam is an extremely powerful chant.It is said that Devi Herself ordered that this chant should be propagated and spread.
It is said it was given to Hayagriva an incarnation of Mahavishnu with the head of a horse ,when Hayagriva was in thirst of getting liberation , mukti.
By chanting the Lalitha Sahasranamam with devotion,Hayagriva was blessed with the Divine Mother Herself appearing and giving him Mukti ( liberation )
Lalitha Sahasranamam came directly from Lord Shiva,who passed it to Nandi.From Nandi,it went to Lord Hayagriva and then to Sage Agasthiyar
Lalitha Sahasranama is taken from Brahmanada Purana and divided into three parts.
The first one is called ‘Poorva Bhaga’ the middle portion which is called ‘Stotra’ which consists of 1000 Namas (names) and the last portion is called ‘Uttara Bhaga’.
The Poorva Bhaga talks about its origin. The Uttara Bhaga gives details of the benefits of recitation of this Lalitha Sahasranamam.
Lalitha sahasranama is said to have been composed by eight Vaag Devis (vaag Devathas) upon the command of Lalitha. These vaag devis are Vasini, Kameshwari, Aruna, Vimala, Jayinee, Modhinee, Sarveshwari, and Koulini. The sahasranama says that “One can worship Lalitha only if she wishes us to do so”. The text is a dialogue between Hayagriva, an (avatar) of Mahavishnu and the sage Agastya. The temple at Thirumeyachur near Kumbakonam is said to be where Agastya was initiated into this sahasranama. Another alternative version is the Upanishad Bramham Mutt at Kanchipuram is where this initiation happened.
This sahasranama is held as a sacred text for the worship of the “Divine Mother”, Lalita, and is used in the worship of Durga, Parvati, Kaali, Lakshmi, Saraswati, Bhagavathi, etc. A principal text of Shakti worshipers, it names her various attributes and these names are organized in the form of a hymn. This Sahasranama is used in various modes for the worship of the Divine Mother. Some of the modes of worship are Parayana (Recitations), Archana, Homa etc.