"To Mary, His faithful Spouse, God the Holy Ghost has communicated His unspeakable gifts; and He has chosen her to be the dispensatrix of all He possesses, in such sort that she distributes to whom she wills, as much as she wills, as she wills, and when she wills, all His gifts and graces. The Holy Ghost gives no heavenly gift to men which He does not pass through her virginal hands. Such has been the Will of God, who has willed that we should have everything in Mary; so that she who impoverished, humbled, and hid herself even to the abyss of nothingness by her profound humility her whole life long, should now be enriched, and exalted by the Most High. Such are the sentiments of the Church and the Holy Fathers.
[...] Inasmuch as grace perfects nature, and glory perfects grace, it is certain that our Lord is still, in heaven, as much the Son of Mary as He was on earth; and that, consequently, He has preserved the most perfect obedience and submission of all children towards the best of all mothers. But we must take great pains not to conceive of this dependence as any abasement or imperfection in Jesus Christ. For Mary is infinitely below her Son, who is God, and therefore she does not command Him, as a mother here below would command her child, who is below her. Mary, being altogether transformed into God by grace, and by the glory which transforms all the Saints into Him, asks nothing, wishes nothing, does nothing which is contrary to the Eternal and Immutable Will of God. When we read, then, in the writings of SS. Bernard, Bernardine, Bonaventure, and others, that in heaven and on earth everything, even to God Himself, is subject to the Blessed Virgin, they mean to say that the authority which God has been well pleased to give her is so great, that it seems as if she has the same power as God, and that her prayers and petitions are so powerful with God, that they always pass for commandments with His Majesty, who never resists the prayer of His dear Mother, because she is always humble and conformed to His Will.
If Moses, by the force of his prayer, arrested the anger of God against the Israelites, in a manner so powerful that the Most High and infinitely merciful Lord, being unable to resist him, told him to let Him alone, that He might be angry with and punish that rebellious people, what must we not with much greater reason think of the prayer of the humble Mary, that worthy Mother of God, which is more powerful with His Majesty than the prayers and intercessions of all the Angels and Saints both in heaven and on earth?"
St. Louis de Montfort, True Devotion to Mary