Shiva Purana
नानोपायैर्यदा राज्ञस्तीर्थस्नानादिभिर्द्विजाः ॥ न निवृत्ता ब्रह्महत्या मिथिलां स ययौ तदा ॥ ३०॥
O brahmins, when Brahmahatyā did not leave him inspite of the means like the ceremonial ablution in holy centres, the king went to Mithilā.
english translation
nAnopAyairyadA rAjJastIrthasnAnAdibhirdvijAH ॥ na nivRttA brahmahatyA mithilAM sa yayau tadA ॥ 30॥
hk transliteration by Sanscript