Gregory the Great — on Ezek 1:4 (Homilies on Ezekiel, Book 1, Homily 2)

“"And behold a whirlwind came from the North, and a great cloud." Because the north wind constrains with cold, the torpor of the malignant spirit is not unfittingly designated by the name of the north wind. The prophet Isaiah also testifies to this, who declares that the devil said: "I will sit upon the mountain of the testament, in the sides of the north." For the malignant spirit held the mountain of the testament, because he subjugated the Jewish people, who had received the law, to himself in faithlessness. For when he holds the hearts of teachers, the devil presides over the mountain of the testament. He also sits in the sides of the north, because he possesses the cold minds of men. Whence also it is said in the voice of the bridegroom in the Song of Songs: "Arise, O north wind, and come, O south wind, blow through my garden, and let its spices flow forth." For when, at the Lord's command, the cold spirit withdraws, the warm spirit occupies the mind of the faithful; which blows through God's garden, that is, the holy Church, so that the fragrances of its virtues may flow forth to the knowledge of many like spices. For when the north wind withdraws, that is, the malignant spirit, the Holy Spirit fills the mind like the south wind. When He blows by warming, immediately the spices of virtues flow from the hearts of the faithful. Therefore the prophet, seeing what things were to come at the end, saw a wind of whirlwind coming from the north, because at the end of the age the malignant spirit will more grievously occupy the minds of men with the cold of his torpor. Whence it is written: "Woe to the earth and to the sea, because the devil has descended to you having great wrath, knowing that he has but a short time." For the ancient adversary has more grievously intensified the efforts of his treacheries in human minds. Against his growing pride, the humility of the incarnate God was made manifest: and so that He might heal the human race from its weakness, then the great power of the physician appeared, when the sickness of the patient increased.”