Śaiśirīya Śikṣā 25

25

anusvāre vivṛtyante virāme cākṣaradvaye
ovarṇe ca uvarṇe ca pavarge ca pṛthak pṛthak

Upon an anusvāra, hiatus occurs, and at a pause between two syllables; / and upon the o-vowel, upon the u-vowel, and upon the pa-class, separately;