Excerpts from the Homily on the Dormition
For this reason she pours forth from thence abundant grace upon those who honor her-for she is a receptacle of great graces-and she grants us even our ability to look towards her. Because of her goodness she lavishes sublime gifts upon us and never ceases to provide a profitable and abundant tribute in our behalf. If a man looks towards this concurrence and dispensing of every good, he will say that the Virgin is for virtue and those who live virtuously, what the sun is for perceptible light and those who live in it.
...in the endless age to come, without her mediation, every emanation of illuminating divine light, every revelation of the mysteries of the Godhead, every form of spiritual gift, will exceed the capacity of every created being. She alone has received the all-pervading fulness of Him that filleth all things, and through her all may now contain it, for she dispenses it according to the power of each, in proportion and to the degree of the purity of each. Hence she is the treasury and overseer of the riches of the Godhead. For it is an everlasting ordinance in the heavens that the inferior partake of what lies beyond being, by the mediation of the superior, and the Virgin Mother is incomparably superior to all. It is through her that as many as partake of God do partake
It seems to me that Palamas is saying that she is mediatrix of all grace by physical instrumental causality and not merely morally by way of prayer. What is your interpretation?O divine, and now heavenly, Virgin, how can I express all things which pertain to thee? ... The eye of the intellect is through thee made limpid, and through thee the spirit of a man is illumined by the sojourning of the Spirit of God, since thou hast become the steward of the treasury of divine gifts and their vault, and this, not in order to keep them for thyself, but so that thou mightest make created nature replete with grace. Indeed, the steward of those inexhaustible treasuries watches over them so that the riches may be dispensed; and what could confine that wealth which wanes not? Richly, therefore, bestow thy mercy and thy graces upon all thy people, this thine inheritance, O Lady! Dispel the perils which menace us. See how greatly we are expended by our own and by aliens, by those without and by those within. Uplift all by thy might: mollify our fellow citizens one with another and scatter those who assault us from without-like savage beasts. Measure out thy succor and healing in proportion to our passions, apportioning abundant grace to our souls and bodies, sufficient for every necessity. And although we may prove incapable of containing thy bounties, augment our capacity and in this manner bestow them upon us, so that being both saved and fortified by thy grace,... Amen.