Gr. hoti, which has the two basic meanings “that,” or “because.” Either meaning makes good sense here.

 That is, Mary, who is here congratulated for her faith and for the high honor that has come to her. Perhaps Elisabeth was thinking of her husband‘s unbelief, and of the evidence of divine disfavor that resulted. God is honored and pleased when His earthborn children accept His promises in humble and unquestioning faith. “Blessed are they that have not seen, and yet have believed” (John 20:29).