Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 39: Sagara’s Sons Search for the Sacrificial Horse
Text 1.39.3

तस्य तद्वचनं श्रुत्वा कौतूहलसमन्वितः।
विश्वामित्रस्तु काकुत्स्थमुवाच प्रहसन्निव।
श्रूयतां विस्तरो राम सगरस्य महात्मनः॥

tasya tad vacanaṁ śrutvā kautūhala-samanvitaḥ
viśvāmitras
tu kākutstham uvāca prahasann iva
rūyatāṁ
vistaro rāma sagarasya mahātmanaḥ

tasya tat vacanam śrutvā = hearing those words of Śrī Rāma; kautūhala-samanvitaḥ = became excited and; viśvāmitraḥ tu = Viśvāmitra; kākutstham = the descendant of Kakutstha; uvāca = told; prahasan iva = smilingly; śrūyatām = listen; vistaraḥ = to the details; rāma = O Rāma; sagarasya = regarding the sacrifice of Sagara; mahā-ātmanaḥ = the great soul.

Hearing those words of Śrī Rāma, Viśvāmitra became excited and smilingly told the descendant of Kakutstha: O Rāma, listen to the details regarding Sagara’s sacrifice.

Prahasann iva: Viśvāmitra smiled because Lord Rāma had asked him about that very topic that he wanted to elaborate on and because He asked him as if He didn’t know about it.