Vaṃśānuvārṇana and the Transition to the Fourth (Upasaṃhāra) Pada
भस्म सर्वमनुप्राप्य तस्मादंभो निरुच्यते / नानात्वे चैव शीघ्रे च धातुर्वै अर उच्यते
bhasma sarvamanuprāpya tasmādaṃbho nirucyate / nānātve caiva śīghre ca dhāturvai ara ucyate
Sacred ash pervades all; therefore it is explained as “ambhaḥ.” And for the sense of diversity and swiftness, the verbal root “ar” is indeed spoken of.