ISB ~ Luke 1 v34

How can this be:Or, better, “How will this be … ?” Mary is not questioning God’s ability to give her a son, but she is inquiring as to how such a plan will unfold. I have no husband: The Greek text literally reads “I do not know man”, which refers to Mary’s virginal status rather than her marital status. Her concern is not that she is unmarried but that she is a virgin at present and that she intends to remain one in the future. The announcement of a miraculous conception (1:31) thus causes Mary to wonder aloud how God will bless her with a son and yet preserve her virginal purity. Her words are inexplicable otherwise. For nothing about the angel’s announcement should have perplexed Mary—whose betrothal to Joseph was already a legally binding marriage—unless she intended to forego ordinary sexual relations even as a married woman. See note on Mt 1:18.

• According to certain Church Fathers, such as St. Gregory of Nyssa and St. Augustine, Mary had previously taken a vow of lifelong virginity. See notes on Mt 1:25 and 12:46.