For Elizabeth and her husband Zechariah, this was not merely the fulfilment of a prophecy given six months previously - although that was clearly important. It was also the gift of a child for whom they had longed throughout their adult lives and into old age. The yearning for a child had not diminished their faith in God, even though they had waited beyond the point at which childbirth seemed a possibility. And now, surprisingly, fulfilment was near.
For Mary, on the other hand, this was something very new indeed. Thought to have been only a teenager, and in scandalous circumstances, she nevertheless looked forward to the work of God through the son to be born to her. Doubtless she was encouraged and comforted by the words of her cousin: 'Blessed is she who believed that there would be a fulfilment of what was spoken to her by the Lord.'
In this encounter, we see God at work in God's own time - over a lifetime of faithful preparation, and in someone barely more than a child. We see the unfolding of God's promises not as we might expect or hope, but in unexpected ways and in unexpected people. And if we pause to think about it, we realise that the fulfilment of God's promises was taking place not only through the months of these two pregnancies, but over decades as John and Jesus grew to maturity and took up their vocations.
Indeed, the fulfilment of God's promise to Mary is still being worked out centuries later, as we discover God-with-us in Jesus.
No wonder Mary responded with that great outpouring of praise we call the Magnificat:
'My soul magnifies the Lord, and my spirit has rejoiced in God my Saviour.'