Valmiki Ramayana Yuddha Kanda Sarga 110 Shloka 37

देवदानवयक्षाणाम् Devas, Danavas, Yakshas, पिशाचोरगरक्षसाम् demons, Nagas, and Rakshasas, पश्यताम् watched, तत् that, महायुद्धम् great war, सप्तरात्रम् seven nights and days, अवर्तत continued

The Devas, Danavas, Yakshasas also the fiends Demon, Nagas and Rakshasas watched the great war that continued for seven days and nights.