After the annunciation, Mary does an intriguing thing:
In those days Mary arose and went with haste into the hill country, to a town in Judah. And she entered the house of Zachariah and greeted Elizabeth.
Which raises the question, why? Why go with haste, why straight to Elizabeth? What is running through her mind as she hurries to the hill country?
We don’t know for sure, of course, and even without knowing this is one of the personal touches that makes the gospel story so compelling. It is about real people, real emotions, real motivations, and that shines through to me in Mary’s reaction to the angel’s news.
Nevertheless, there are some clues in the narrative. We can know a few things about how Mary responded to Gabriel’s announcement. There was some doubt in her question “how can this be, since I am a virgin?”, since Gabriel finds it necessary not only to explain literally how it can be (v. 35), but also to provide Elizabeth’s pregnancy as a proof of God’s power - “for nothing will be impossible with God” (vv. 36-37).
It seems likely that Mary had not known about Elizabeth’s pregnancy. Gabriel says “Behold, your relative Elizabeth in her old age has also conceived a son”, as if he is telling her rather than reminding her. Also, Elizabeth “kept herself hidden” for the first five months of her pregnancy (v. 24).
So Gabriel has given Mary a clear, verifiable sign of the power of God that is at work in her: Elizabeth is 6 months pregnant (v. 26, 36), and she will have a son.
Mary’s haste can be partly explained, then, by a need to confirm the angel’s sign. That also explains why she stayed 3 months (v. 56), probably until shortly after the birth of John the Baptist.
This needn’t be taken as act of skepticism (“is Elizabeth really pregnant?). Although there was some doubt in her question, her submission to the will of God is total (“Behold I am the servant of the Lord, let it be to me according to your word” v. 38). Also, Elizabeth greets her with “blessed is she who believed that there would be a fulfillment of what was spoken to her from the Lord” (v. 45), words that confirm her faith and contrast her with Elizabeth’s own husband, who reacted with skepticism to the angel’s announcement of John’s birth (v. 18).
Mary must go and see with her own eyes this thing that God is doing. Even in the midst of her words of submission to the angel, you can’t help but feel her mind racing, the inner turmoil that impels her hasty journey to Elizabeth. Perhaps the Spirit at work in her was calling to the Spirit at work in Elizabeth - they certainly greeted each other with outpourings of the Spirit (vv 41-45, 46-55).