Shiva Purana
सुतो विदर्भराजस्य शिवभक्तस्य धीमतः ॥ अयं सत्यरथस्यैव स्वधर्मनिरतस्य हि ॥ ३७॥
This boy is the son of Satyaratha, king of Vidarbha a great devotee of Śiva and devoted to his duty.
english translation
suto vidarbharAjasya zivabhaktasya dhImataH ॥ ayaM satyarathasyaiva svadharmaniratasya hi ॥ 37॥
hk transliteration by Sanscript