Canto 2 -
Ayodhyā-kāṇḍa
Chapter 46: Rāma Leaves the Brāhmaṇas to go to the Forest
Text 2.46.10

अद्भिरेव तु सौमित्रे वत्स्याम्यद्य निशामिमाम्।
एतद्धि रोचते मह्यं वन्येऽपि विविधे सति॥

adbhir eva tu saumitre vatsyāmy adya niśām imām
etad dhi rocate mahyaṁ vanye ’pi vividhe sati

adbhiḥ = on water; eva tu = alone; saumitre = Lakṣmaṇa; vatsyāmi = I will subsist; adya niśām imām = tonight; etat = this; hi = alone; rocate = is pleasing; mahyam = to Me; vanye = of forest foods; api = though; vividhe = a variety; sati = are available.

Lakṣmaṇa, I will subsist on water alone tonight. Though a variety of forest foods are available, this alone is pleasing to Me.1

Rāma fasted [thus] because it was the first day of His residence in the forest and because the bank of Tamasā was a sacred spot. Subsisting on water alone pleased Him because He remembered the distress of people who loved Him.1

GLOSS. It is hinted herewith that Rāma fasted in that sacred spot because His father had a short span of life to live. 

1 The forest foods are, as will become repeatedly clear in the Rāmāyaṇa, fruits and roots.

1 Here Rāma demonstrates His opulence of renunciation to teach us the importance of reducing even acceptable forms of sense enjoyment while residing in a sacred spot.