atha rājño babhūvaivaṃ vṛddhasya cirajīvinaḥ prītireṣā kathaṃ rāmo rājā syānmayi jīvati|
Thereafter, flashed in the mind of that aged king who had (already) lived long this pleasant thought as to how Rama will become king while he was alive.
— M.N. Dutt (1891)
The thought that flashes in Dasharatha's mind is the coronation of Rama. The phrase 'pleasant thought' (priyaṃ) is poignant because the reader knows what will happen to this plan. The joy of this moment is shadowed by the grief to come — the epic's finest dramatic irony.