Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 19: Viśvāmitra Requests Daśaratha to Give Rāma
Text 1.19.7
न च मे क्रोधमुत्स्रष्टुं बुद्धिर्भवति पार्थिव।
तथाभूता हि सा चर्या न शापस्तत्र मुच्यते॥
na ca me krodham utsraṣṭuṁ buddhir bhavati pārthiva
tathā-bhūtā hi sā caryā na śāpas tatra mucyate
na ca me = I don’t; krodham utsraṣṭum = to become angry; buddhiḥ = the mind; bhavati = have; pārthiva = O king; tathā-bhūtā hi = is such that; sā = the; caryā = sacrificial performance; na = no; śāpaḥ = curse; tatra = there; mucyate = can be uttered.
O king, I don’t have the mind to become angry. The sacrificial performance is such that no curse can be uttered there.
This verse explains why the sage didn’t curse the two rākṣasas.