Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 21: The Anger and Appeasal of Viśvāmitra
Text 1.21.2

पूर्वमर्थं प्रतिश्रुत्य प्रतिज्ञां हातुमिच्छसि।
राघवाणामयुक्तोऽयं कुलस्यास्य विपर्ययः॥

pūrvam arthaṁ pratiśrutya pratijñāṁ hātum icchasi
rāghavāṇām
ayukto ’yaṁ kulasyāsya viparyayaḥ

pūrvam = first; artham pratiśrutya = you promised me that you will fulfill my request and now; pratijñām = that promise; hātum = to break; icchasi = you want; rāghavāṇām = of Raghu’s descendants; ayuktaḥ = is inappropriate; ayam = such; kulasya-asya = for the dynasty; viparyayaḥ = breaking of promises.

You first promised me that you will fulfill my request and now you want to break that promise. Such breaking of promises is inappropriate for the dynasty of Raghu’s descendants.