Chandogya Upanishad 2.12.1

2.12.1

abhimanthati sa (S )kāraḥ \
dhūmo jāyate sa prastāvaḥ \
jvalati sa udgīthaḥ \
aṅgārā bhavanti sa pratihāraḥ \
upaśāmyati tan nidhanam \
saṃśāmyati tan nidhanam \
etad rathaṃtaram agnau protam \\212.1\

1. One rubs the fire-sticks together—that is a Hiṅkāra.
Smoke is produced—that is a Prastāva.
It blazes—that is an Udgītha.
Coals are formed—that is a Pratihāra.

It becomes extinct—that is a Nidhana. It becomes completely extinct—that is a Nidhana. This is the Rathantara Sāman as woven upon fire.