Ramayana
दीयते द्वन्द्वयुद्धं ते राक्षसाधिपते मया । सन्तिष्ठ क्षिप्रमायत्तो भव चैवं भवाम्यहम् ॥ 7-19-10 ॥
"Single combat is granted to you by me, O lord of the rakshasas. Stand firm and make yourself ready at once, even as I make myself ready."
english translation