Blessed Athansius stating Mary was “clothed with purity” means sinless. Your modern thinking of purity is flawed by only having sexual meaning to it.
Of course there are other references by him for that supposition?
Yet if one were to accept this supposition, why wasn't this understanding, that is in conflict with Scripture, not included in his creed which lays out the catholic faith? After all he includes in his creed this: it is necessary to everlasting salvation that he also believe faithfully the incarnation of our Lord Jesus Christ.
I guess this should have been my answer to the Catholic FReeper who asked "How can you ever talk about the idea of the incarnation without bringing her into the matter." (sic) Apparently Athanasius found no need to include Mary's participation in the Incarnation other then recognizing it as a Virgin birth.
That may be, but since no one but Christ was sinless, that is sufficient.