SB 11.21.12
dhanya-darv-asthi-tantunam
rasa-taijasa-carmanam
kala-vayv-agni-mrt-toyaih
parthivanam yutayutaih
Translation:
Various objects such as grains, wooden utensils, things made of bone, thread, liquids, objects derived from fire, skins and earthy objects are all purified by time, by the wind, by fire, by earth and by water, either separately or in combination.
Purport:
The word kala, or “time,” is mentioned here, since all purificatory processes take place within time.