Valmiki Ramayana Aranya Kanda Sarga 50 Shloka 22
Original Shlokaयुद्ध्यस्व यदि शूरोऽसि मुहूर्तं तिष्ठ रावण।।3.50.22।। शयिष्यसे हतो भूमौ यथापूर्वं खरस्तथा।
1 source checked for this shloka
रावण O Ravana, शूरः असि यदि if you are a hero, युद्ध्यस्व do fight with me, मुहूर्तम् तिष्ठ stay awhile, पूर्वम् earlier, खरः Khara, यथा as he was, तथा likewise, हतः slayed, भूमौ on the earth, शयिष्यसे will sleep.
O Ravana, if you are brave, fight with me. In a moment, you will be killed like Khara and lie down on the ground.