While many versions of the tale exist, Ila is usually described as a daughter or son of Vaivasvata Manu and thus the sibling of Ikshvaku, the founder of the Solar Dynasty.

The tale of Ila's transformations is told in the Puranas as well as the Indian epic poems, the Ramayana and the Mahabharata.

According to the Linga Purana and the Mahabharata, Ilā was born as the eldest daughter of Vaivasvata Manu, the progenitor of mankind, and his wife Shraddha.

However, the parents desired a son and so prayed and performed austerities to propitiate the deities Mitra and Varuna, who changed Ilā's gender.

The sage performed a yajna (fire sacrifice) dedicated to Mitra and Varuna to attain a son for the couple.

Ila's tale is told in the Uttara Kanda chapter of the Ramayana, while describing the greatness of the Ashvamedha – the horse sacrifice.

Upon entering Sharavana, all-male beings except for her husband Shiva, including trees and animals, are transformed into females.

[Notes 1] One legend tells that a female yakshini disguised herself as a deer and purposefully led Ila to the grove in order to save her husband from the king.

[11] The Linga Purana and the Mahabharata emphasize the sex change of Ila to be a deliberate act of Shiva to start the Lunar dynasty.

[1] The Bhagavata Purana et al. texts tell that Ila's entire entourage, as well as his horse, also changed their genders.

While Ilā roamed the forest in her new form with her female attendants, Budha, the god of the planet Mercury and the son of the moon-god Chandra, noticed her.

During each month as a man, Ila turned to pious ways and performed austerities under the guidance of Budha.

In the ninth month, Ilā gave birth to Pururavas, who grew to become the first king of the Lunar dynasty.

[3][4][9] The Linga Purana and the Mahabharata record the birth of Pururavas, but do not narrate the end of Ila's alternating gender condition.

The king Ela (Ila) entered Parvati's grove at Sahya mountain and became the woman Ilā.

Ilā wished to remain a woman and serve Parvati (Gauri) and Ganga, the goddess of the Ganges river.

Ila's father passed his inheritance directly to Pururavas, ignoring the three sons Ila-Sudyumma bore as a male.

[9][23] The marriage of Ilā, a descendant of the Sun, and Budha, the son of the Moon, is the first union of the solar and lunar races recorded in the scriptures.

She is described as the Mānavi (daughter of Manu) and Ghṛtapadī (with the ghee-dripping foot) and she is represented by a cow, also known as Idā during a sacrifice.