(1) Keeing the Law does not necessitate impurity. (shown in 469)
(2) Mary kept the Law.
Therefore
(3) Mary's keeping the Law does not necessite any impurity in her.
-A8
"(1) Keeing the Law does not necessitate impurity
(2) Mary kept the Law.
Therefore
(3) Mary's keeping the Law does not necessite any impurity in her."
That's nice but it does not correspond with reality.
(1) The law states that a woman who births a male child is impure and must undergo the purification rites.
(2) Mary births a male child.
Therefore,
(3) Under the Law, Mary is impure and must undergo the purification rites.
That's the reality of the situation according to the scripture.