He giveth snow like wool: he scattereth the hoarfrost like ashes.

Wesley's Notes

147:16 Like wool - Not only in colour and shape, and softness, but also in use, keeping the fruits of the earth warm. Ashes - In colour and smallness of parts, as also in its burning quality.

Matthew Henry's Concise Commentary

147:12-20 The church, like Jerusalem of old, built up and preserved by the wisdom, power, and goodness of God, is exhorted to praise him for all the benefits and blessings vouchsafed to her; and these are represented by his favours in the course of nature. The thawing word may represent the gospel of Christ, and the thawing wind the Spirit of Christ; for the Spirit is compared to the wind, Joh 3:8. Converting grace softens the heart that was hard frozen, and melts it into tears of repentance, and makes good reflections to flow, which before were chilled and stopped up. The change which the thaw makes is very evident, yet how it is done no one can say. Such is the change wrought in the conversion of a soul, when God's word and Spirit are sent to melt it and restore it to itself.