John Gill, on Luke 1:46

And Mary said, my soul doth magnify the Lord. Either Jehovah, the Father, or the Son; who, as he was David's Lord, according to his divine nature, though his son after the flesh, was, in the same sense, Mary's Lord, as well as her son: and by "magnifying" him is meant, not making him great, for he cannot be made greater than he is; but ascribing greatness to him, even all the perfections of the Deity, and praising him on account of them; and also declaring and speaking well of his many and mighty works of power, goodness, grace, and mercy, and giving him the glory of them: this Mary did, not in lip and word only, but with her whole heart and, soul, and with all the powers and faculties of it; being filled with the Holy Ghost, and under a more than ordinary influence of his, as her cousin Elisabeth was: and it is to be observed, that she all along speaks in the prophetic style, of things, as if they were done, which were doing, or would shortly be done. And Mary said, my soul doth magnify the Lord. Either Jehovah, the Father, or the Son; who, as he was David's Lord, according to his divine nature, though his son after the flesh, was, in the same sense, Mary's Lord, as well as her son: and by "magnifying" him is meant, not making him great, for he cannot be made greater than he is; but ascribing greatness to him, even all the perfections of the Deity, and praising him on account of them; and also declaring and speaking well of his many and mighty works of power, goodness, grace, and mercy, and giving him the glory of them: this Mary did, not in lip and word only, but with her whole heart and, soul, and with all the powers and faculties of it; being filled with the Holy Ghost, and under a more than ordinary influence of his, as her cousin Elisabeth was: and it is to be observed, that she all along speaks in the prophetic style, of things, as if they were done, which were doing, or would shortly be done. Luke 1:47 luk 1:47 luk 1:47 luk 1:47And my spirit hath rejoiced in God my Saviour. Which also, may be understood, either of God the Father, who was her Saviour, both as the God of nature and providence; so the Persic version renders it, "in God that gives me life"; and who had supported, maintained, and preserved her life; and as the God of grace, who has contrived the scheme of salvation, fixed upon, and appointed Christ to be the Saviour; and who saves by him, and therefore is sometimes said to be our Saviour. Tit 3:4 or of Christ, the Son of God, who being truly and properly God, was fit to be a Saviour; and is a very suitable, able, and willing one; and which is the great encouragement to sensible sinners, to look up to him, and be saved; and lays a solid foundation for rejoicing in him, since what he did as man, had hereby an infinite virtue and efficacy put into it, as was put into his blood, sacrifice, and righteousness; whereby the purposes designed were answered by them; and since he must be able to keep their immortal souls, which they commit unto him, and must have an interest with his Father, as their advocate, and a fulness, to supply all their wants: the consideration of Christ, by Mary, as God her Saviour, as having an interest in him, as a Saviour, and this her Saviour, God, gave her greater joy, than being the mother of him as man; and this her joy was not carnal, nor merely external, but inward and spiritual: it was a joy in her own spirit, and was excited there by the holy Spirit of God.