The interpretation timeline
Luke 1:46 Douay-Rheims

And Mary said: My soul doth magnify the Lord.

A.D. 253 – 1871 7 witnesses

Patristic

before A.D. 750
253
A.D.
Origen Patristic
c. A.D. 184–253
“Now if the Lord could neither receive increase or decrease, what is this that Mary speaks of, My soul doth magnify (magnificat) the Lord? But if I consider that the Lord our Saviour is the image of the invisible God, and that the soul is created according to His image, so as to be an image of an image, then I shall see plainly, that as after the manner of those who are accustomed to paint images, each one of us forming his soul after the image of Christ, makes it great or little, base or noble, after the likeness of the original; so when I have made my soul great in thought, word, and deed, the image of God is made great, and the Lord Himself, whose image it is, is magnified in my soul.”
Source
379
A.D.
Basil of Caesarea Patristic
c. A.D. 330–379
“(in Psalm 33) For the Virgin, with lofty thoughts and deep penetration, contemplates the boundless mystery, the further she advances, magnifying God; And Mary said, My soul doth magnify the Lord.”
397
A.D.
Ambrose of Milan Patristic
A.D. 339–397
“As evil came into the world by a woman, so also is good introduced by women; and so it seems not without meaning, that both Elisabeth prophesies before John, and Mary before the birth of the Lord. But it follows, that as Mary was the greater person, so she uttered the fuller prophecy.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“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.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“And Mary said - Two copies of the Itala, and some books mentioned by Origen, give this song to Elisabeth. It is a counterpart of the song of Hannah, as related in Sa1 2:1-10. This is allowed by many to be the first piece of poetry in the New Testament; but the address of the angel to Zacharias, Luk 1:13-17, is delivered in the same way; so is that to the virgin, Luk 1:30-33, and so also is Elisabeth's answer to Mary, Luk 1:42-45. All these portions are easily reducible to the hemistich form in which the Hebrew poetry of the Old Testament is found in many MSS., and in which Dr. Kennicott has arranged the Psalms, and other poetical parts of the Sacred Writings. See his Hebrew Bible. My soul doth magnify the Lord - The verb μεγαλυνειν, Kypke has proved, signifies to celebrate with words, to extol with praises. This is the only way in which God can be magnified, or made great; for, strictly speaking, nothing can be added to God, for he is infinite and eternal; therefore the way to magnify him is to show forth and celebrate those acts in which he has manifested his greatness.”
Source
1871
A.D.
1871
“A magnificent canticle, in which the strain of Hannah's ancient song, in like circumstances, is caught up, and just slightly modified and sublimed. Is it unnatural to suppose that the spirit of the blessed Virgin had been drawn beforehand into mysterious sympathy with the ideas and the tone of this hymn, so that when the life and fire of inspiration penetrated her whole soul it spontaneously swept the chorus of this song, enriching the Hymnal of the Church with that spirit-stirring canticle which has resounded ever since from its temple walls? In both songs, those holy women, filled with wonder to behold "the proud, the mighty, the rich," passed by, and, in their persons the lowliest chosen to usher in the greatest events, sing of this as no capricious movement, but a great law of the kingdom of God, by which He delights to "put down the mighty from their seats and exalt them of low degree." In both songs the strain dies away on CHRIST; in Hannah's under the name of "Jehovah's King"--to whom, through all His line, from David onwards to Himself, He will "give strength"; His "Anointed," whose horn He will exalt (Sa1 2:10); in the Virgin's song, it is as the "Help" promised to Israel by all the prophets. My soul . . . my spirit--"all that is within me" (Psa 103:1).”
Source

Undated

date unknown
date
unknown
“(Athanasius.) As if she said, Marvellous things hath the Lord declared that He will accomplish in my body, but neither shall my soul be unfruitful before God. It becomes me to offer Him the fruit also of my will, for inasmuch as I am obedient to a mighty miracle, am I bound to glorify Him who performs His mighty works in me.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.