Ramayana
इष्ट्वा तु राजसूयेन मित्रः शत्रुनिबर्हणः । सुहुतेन सुयज्ञेन वरुणत्वमुपागमत् ॥ 7-83-6 ॥
"For Mitra, the destroyer of foes, having offered the Rajasuya with well-poured oblation and well-conducted sacrifice, attained the rank of Varuna."
english translation