Canto 2 -
Ayodhyā-kāṇḍa
Chapter 19: Rāma Promises to Leave for the Forest
Text 2.19.37

उचितं च महाबाहुर्न जहौ  हर्षमात्मनः।
शारदः समुदीर्णांशुश्चन्द्रस्तेज इवात्मजम्॥

ucitaṁ ca mahā-bāhuḥ na jahau harṣam ātmanaḥ
śāradaḥ samudīrṇāṁśuś candras teja ivātmajam

ucitam ca = appropriate; mahā-bāhuḥ = the great armed Rāma; na = not; jahau = did give up; harṣam = cheerfulness; ātmanaḥ = His; śāradaḥ = the autumnal; samudīrṇa-aṁśuḥ = with its enhanced rays; candraḥ = moon; tejaḥ = prowess; iva = just as; ātmajam = [does not give up] its natural.

The great armed Rāma did not give up His appropriate cheerfulness just as the autumnal moon with its enhanced rays [does not give up] its natural prowess.

Lord Rāmacandra’s appropriate cheerfulness was natural to Him.