Psalms 147:18

He sendeth out his word, and melteth them: he causeth his wind to blow, and the waters flow.

God sends forth His word to dissolve ice, and He makes His wind blow so that the bound waters are released and flow again. The thaw is His direct act, not the working of matter on its own. No shift in nature stands alone as an independent process, for He furnishes whatever each change requires. He carries out His intentions through agencies He has created, employing them as His instruments.