Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 2: Lord Brahmā Instructs Vālmīki
Text 1.2.39

तस्य शिष्यास्ततः सर्वे जगुः श्लोकमिमं पुनः।
मुहुर्मुहुः प्रीयमाणाः प्राहुश्च भृशविस्मिताः॥

tasya śiṣyās tataḥ sarve jaguḥ ślokam imaṁ punaḥ
muhur muhuḥ prīyamāṇāḥ prāhuś ca bhṛśa-vismitāḥ

tasya = his; śiṣyāḥ = disciples; tataḥ = then; sarve = all of; jaguḥ = sang; ślokam = the śloka (text 15); imam = about this; punaḥ = repeatedly; muhuḥ muhuḥ = again and again; prīyamāṇāḥ = and happiness; prāhuḥ = they spoke; ca = and; bhṛśa-vismitāḥ = with extreme astonishment and happiness.

Then his disciples repeatedly sang the śloka (text 15) and again and again they spoke to each other with extreme astonishment about this.