Augustine on the Perpetual Virginity of Mary
For, inasmuch as He was born of a mother who, although she conceived, was untouched by man and always remained untouched, a virgin in conception, a virgin in childbearing, a virgin in death.
Augustine: The First Catechetical Instruction (De Catechizandis Rudibus) 22.40
English translation from Ancient Christian Writers, Vol. 2, page 71