It is very good for those who have the work of grace begun in their souls, to communicate one to another. On Mary's arrival, Elisabeth was conscious of the approach of her who was to be the mother of the great Redeemer. At the same time she was filled with the Holy Ghost, and under his influence declared that Mary and her expected child were most blessed and happy, as peculiarly honoured of and dear to the Most High God. Mary, animated by Elisabeth's address, and being also under the influence of the Holy Ghost, broke out into joy, admiration, and gratitude. She knew herself to be a sinner who needed a Saviour, and that she could no otherwise rejoice in God than as interested in his salvation through the promised Messiah. Those who see their need of Christ, and are desirous of righteousness and life in him, he fills with good things, with the best things; and they are abundantly satisfied with the blessings he gives. He will satisfy the desires of the poor in spirit who long for spiritual blessings, while the self-sufficient shall be sent empty away.
SDA Bible Commentary (limited)
Volume 1-7
44. For joy. A figure of speech, attributing to the unborn child this emotion.