Luke 1:42

And she spake out with a loud vote and said, Blessed art thou among women. Thou art most blessed of all women because thou hast been chosen to be the Mother of God Whom the whole world cannot receive.

Blessed is the fruit of thy womb. The fountain of all the blessings and graces bestowed upon the Blessed Virgin by God was to be the mother of God; for God adorned His mother with every grace in order that she might become an habitation worthy of Him, even that she might be worthy to become the Mother of God, and whom would such a Son bless rather than His mother. Elizabeth therefore, by the inspiration of the Spirit knew that Mary had already conceived, and that the Son of God was incarnate in her. And "He is Blessed, not only as thou art, among women, but, absolutely, above angels, men, and all creatures, as being the Creator and Lord of all. Again the rest of the sons of Eve are all under a curse, because they contract original sin from her and from Adam. Christ alone is Blessed because He is not the natural son of Adam, but was supernaturally conceived in the Virgin by the Holy Ghost."

She alludes to the prophecy and promise made to David, Of the fruit of thy body shall I set upon thy seat, Psa 132:2