Valmiki Ramayana 6.89.23
सुदीर्घकालं तौ वीरावन्योन्यं निशितैः शरैः।ततक्षतुर्महात्मानौ रणकर्मविशारदौ॥
sudīrghakālaṃ tau vīrāvanyonyaṃ niśitaiḥ śaraiḥ |tatakṣaturmahātmānau raṇakarmaviśāradau ||
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book