Isaiah 55:10-11

This purpose of salvation is embodied in the word which goes forth from Jehovah's mouth. The "word" is conceived as endowed with a self-fulfilling energy (see on ch. Isaiah 9:8); and its silent but irresistible efficacy is set forth by a beautiful comparison from nature. The same idea was expressed in ch. Isaiah 40:8.

as the rain cometh down &c. The image is suggested by "the heavens" in Isaiah 55:9.

but watereth Rather, without having watered &c.

seed to the sower and bread to the eater Cf. 2 Corinthians 9:10.