Isaiah 55:10-11 — from biblegateway.com
10 As the rain and the snow
come down from heaven,
and do not return to it
without watering the earth
and making it bud and flourish,
so that it yields seed for the sower and bread for the eater,
11 so is my word that goes out from my mouth:
It will not return to me empty,
but will accomplish what I desire
and achieve the purpose for which I sent it.