Forgive, O Lord the offenses of thy servants, that we who by our own deeds are not able to be pleasing unto thee, may by the intercession of the Mother of thy Son our Lord [God] be saved.
Thus a literal translation of the collect which, until Pius XII, was said on Assumption day; after the 1950 proclamation of the dogma of our Lady's Corporal Assumtion, it was replaced by a collect more explicitly asserting the corporality of her Assumption. Incidentally, the word [God] appears in earlier texts and I think it ought to be restored because in this age of weakened faith we ought to lose no opportunity of hammering home the Godness, which is not a misprint for goodness, complete and unambiguous, of the rabbi from Nazareth. This old collect, by the way, survives as one among the options in the new rites for the Common of our Lady, and for use on Saturdays, and for August 5, now seen as the commemoration of the Ephesine definition of Theotokos.
Another reason why this collect might give pause for thought is its apparent assertion that we are 'saved' by the intercession of our Lady. A trifle (as some Anglicans might put it) 'extreme'? I do think this needs unpacking. And so I would make two points. (1) Earlier tradition asks the question "why was she assumed?", and gives an answer quite different from that offered by some modern theologians (i.e. that being immaculate she was not subject to death). She was assumed that she might intercede for us. You will find this in a sermon of the great hesychast Father S Gregory Palamas. This Eastern idea appears also in Western texts such as the Gregorian Sacramentary: "Great, O Lord, in the sight of thy loving kindness is the prayer of the Mother of God, whom thou didst translate from this present age for this reason, that (idcirco ut) she might effectually intercede for our sins before thee". "Let the help, O Lord, of the prayer of the Mother of God come to the aid of thy people; although we know that after the condition of the flesh she left this world, may we know that she prays for us before thee in heavenly glory".
And, (2), I feel we should give a broad sense to the word intercession. Yes, it means that she prays for us. But it also means that Mary came between (cessit inter) God and Man when by her fiat she gave birth to the Divine Redeemer. And, in Mary, function and ontology merge; she is eternally what she was in the mystery of the Incarnation.What she did at Nazareth and Bethlehem is what in the Father's eternal creative utterance she is. And so these two senses of 'intercession' are really one.
That is, surely, the root of the dogma of our Lady as Mediatrix of All Graces.