The hearts of men, once barren of spirituality, shall be made, by the outpouring of the Spirit under Messiah, to bear fruits of righteousness (Isa 5:6; Deu 32:2; 2Sa 23:4; Psa 72:6).
snow - which covers plants from frost in winter; and, when melted in spring, waters the earth.
returneth not - void; as in Isa 55:11; it returns not in the same shape, or without “accomplishing” the desired end.