The Lord sends forth His command (word) and it accomplishes all that He declares. It starts with understanding His word and learning how to apply it to our lives. God's guidance in our lives will never violate His word. Every child of God should long for God's guidance in their lives.
 He giveth snow like wool: He scattereth the hoarfrost like ashes.  He casteth forth His ice like morsels: who can stand before His cold?
God is even sovereign over the weather. Nothing is unaffected by the Lord's cold. The final three verses of this Psalm will help to explain these particular verses better.