There is an interesting story in the Puranas that narrate how Anasuya had the opportunity to become the mother of Trimurtis – Brahma, Vishnu and Shiva. Anasuya was the daughter of Sage Kardama and his wife Devahuti. She was married to the famous Sage Atri. Anasuya was extremely pious and performed intense austerities. Anasuya means one who is free from jealousy and envy. She was also a devoted wife who always followed Dharma.
Legend has it that Brahma, Vishnu and Shiva decided to take a test of Anasuya. They appeared at her Ashram in the form of saints at her ashram. As Sage Atri was not in the ashram, she attended to their needs. The saints told her that they were performing a different kind of austerity and wanted someone who would serve them food naked.
Anasuya could not refuse food to the saints. So she agreed to serve food naked.
So powerful was the Tapa Shakti of Anasuya that her purity turned the three saints into new born babies. She then fed them.
It is said that Goddess Saraswati, Goddess Lakshmi and Goddess Parvati then appeared before Anasuya and pleaded to her to restore the Trimurtis to their original form.
She was offered a boon by the goddesses. As a boon she asked Brahma, Vishnu and Shiva to be born as her sons.
The three gods were born as Dattatreya to Anasuya.
Symbolically the story suggests that Gods go to any length to reward those who follow Dharma. They will become husbands, daughters, sons, brothers to bless those who follow Dharma.