Stories of the Brahma Purana Part-III

In the lineage of Kashyapa and Aditi, Surya, also known as Martanda, was born. He was the sun god, and his wife was Samjna, the daughter of Vishvakarma. They had two sons, Vaivasvata Manu and Yama (Shradhadeva), who had a twin sister named Yamuna. Samjna found it challenging to bear Surya's intense radiance, so she created a replica of herself from her own body, named Chhaya, to take her place. Samjna instructed Chhaya to care for her children and not reveal her true identity.

Samjna went to her father's house but refused to return to Surya due to his powerful energy. Instead, she transformed into a mare and lived in Uttara Kuru.

Unaware of the substitution, Surya had two more sons with Chhaya, Savarni Manu and Shani (Saturn). Chhaya began to show less affection towards Samjna's children, which troubled Yama. In a fit of anger, Yama threatened to kick Chhaya, prompting her to curse him that his legs would fall off. Yama complained to Surya, but he could only reduce the curse's severity, resulting in the creation of worms from the flesh falling from Yama's legs.

Surya questioned Chhaya about her curse and threatened to curse her if she did not reveal the truth. Fearing Surya's wrath, Chhaya finally disclosed the secret.

In a furious state, Surya went to Vishvakarma's house for a solution. Vishvakarma suggested shaving off some of Surya's excess energy to help Samjna bear his radiance. With this energy, Vishvakarma crafted Vishnu's chakra, a formidable bladed weapon.

Surya then traveled to Uttara Kuru in the form of a horse, joining Samjna, who had assumed the form of a mare. In their equine forms, they had two sons named Nasatya and Dasra, collectively known as the Ashvinis, who became the divine physicians of the gods. Afterward, Surya and Samjna resumed their true forms, reconciled, and lived happily together.