Mandhata, who was said to be a chakravarti king (an emperor),utters the Praises of the qualities of Guru Nanak Dev... (Swayye Mahle Pahle Ke, p. 1390) Mandhata or Mandhatri was the son of Yuvanaswa, who belonged to the race of Ikshwaku. Yuvanaswa had no son and no religious rite was organised to procure progeny for him. One night, a consecrated vessel containing water was placed on an altar as a part of the rite. Yuvanaswa woke up during the night and wanted to quench the thirst. He found the water only in the above-mentioned vessel and drank it.
When the sages found that the water had been drunk, they made the query as to who had drunk the same. The king Yuvanaswa said that he had drunk it unwittingly. He conceived and in the course of time gave birth to a child from his right side. The boy, who was named Mandhatri (or Mandhata) grew up and became a mighty monarch. He married Hindumati and by her had three sons and fifty daughters. All the fifty daughters were married to the sage Saibhari.
1. Kohli,Surindar Singh ed,Dictionary of Mythological References in Guru Granth Sahib 1993