Canto 3 -
Araṇya-kāṇḍa
Chapter 10: Rāma Asserts His Unbreakable Resolution to Fulfill His Promises
Text 3.10.14

कामं तपःप्रभावेन शक्ता हन्तुं निशाचरान्।
चिरार्जितं तु नेच्छामस्तपः खण्डयितुं वयम्॥

kāmaṁ tapaḥ-prabhāvena śaktā hantuṁ niśācarān
cirārjitaṁ tu necchāmas tapaḥ khaṇḍayituṁ vayam

kāmam = of course; tapaḥ-prabhāvena = by strength of our ascetic power; śaktāḥ = we are capable; hantum = of killing; niśācarān = the rākṣasas; cira-arjitam = that we have accumulated for a long time; tu = but; na icchāmaḥ = don’t want; tapaḥ = the ascetic power; khaṇḍayitum = to destroy; vayam = we.

Of course, we are capable of killing the rākṣasas by strength of our ascetic power.1 But we don’t want to destroy the ascetic power that we have accumulated for a long time.

They elaborate on this in the next verse.

1 Of course, this power has come about by their meditation on the Supreme Personality of Godhead.