The interpretation timeline
Acts 8:12 Douay-Rheims

But when they had believed Philip preaching of the kingdom of God, in the name of Jesus Christ, they were baptized, both men and women.

A.D. 235 – 1871 6 witnesses

Patristic

before A.D. 750
235
A.D.
Hippolytus of Rome Patristic
c. A.D. 170–235
“But that very sapient fellow Simon makes his statement thus, that there is an indefinite power, and that this is the root of the universe. And this indefinite power, he says, which is fire, is in itself not anything which is simple, as the gross bulk of speculators maintain, when they assert that there are four incomposite elements, and have supposed fire, as one of these, to be uncompounded. Simon, on the other hand, alleges that the nature of fire is twofold; and one portion of this twofold (nature) he calls a something secret, and another (a something) manifest. And he asserts that the secret is concealed in the manifest parts of the fire, and that the manifest parts of the fire have been produced from the secret. And he says that all the parts of the fire, visible and invisible, have been supposed to be in possession of a capacity of perception. The world, therefore, he says, that is begotten, has been produced from the unbegotten fire. And it commenced, he says, to exist thus: The Unbegotten One took six primal roots of the principle of generation from the principle of that fire. For he maintains that these roots have been generated in pairs from the fire; and these he denominates Mind and Intelligence, Voice and Name, Ratiocination and Reflection. And he asserts that in the six roots, at the same time, resides the indefinite power, which he affirms to be Him that stood, stands, and will stand. And when this one has been formed into a figure, He will, according to this heretic, exist in the six powers substantially and potentially. And He will be in magnitude and perfection one and the same with that unbegotten and indefinite power, possessing no attribute in any respect more deficient than that unbegotten, and unalterable, and indefinite power. If, however, He who stood, stands, and will stand, continues to exist only potentially in the six powers, and has not assumed any definite figure, He becomes, says Simon, utterly evanescent, and perishes. And this takes place in the same manner as the grammatical or geometrical capacity, which, though it has been implanted in man's soul, suffers extinction when it does not obtain (the assistance of) a master of either of these arts, who would indoctrinate that soul into its principles. Now Simon affirms that he himself is He who stood, stands, and will stand, and that He is a power that is above all things. So far, then, for the opinions of Simon likewise.”
Source
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“But Philip here by his word also won them over, discoursing concerning the kingdom of Christ. "And Simon," it says, "being baptized, continued with Philip": not for faith's sake, but in order that he might become such as he. And how came he to baptize Simon also? Just as Christ chose Judas. And "beholding the signs" which he did, forasmuch as the others did not receive the power of working signs he durst not ask for it. But why did they not correct him instantly? They were content with his condemning himself. For this too belonged to their work of teaching. But when he had not power to resist, he plays the hypocrite, just as did the magicians, who said, "This is the finger of God." And indeed that he might not be driven away again, therefore he "continued with Philip," and did not part from him.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Then Simon himself believed also,.... With an historical and temporary faith, as that Jesus was the Messiah, &c. or at least he pretended, to believe this, and professed that he did believe, what others did, and Philip preached: and when he was baptized; upon profession of his faith, which he so artfully made, that Philip could not discover his hypocrisy: but taking him to be a sincere believer, admitted him to baptism: after which, he continued with Philip; kept close to him, and got into a familiar acquaintance with him; and constantly attended on his ministry, as if he had been a sincere disciple and follower of Christ: and wondered, beholding the miracles and signs which were done; he was as much amazed at the miraculous performances of Philip, as the inhabitants of Samaria had been at his, which he could observe were real things; and this increased his wonder, and threw him into an ecstasy, that he was scarce himself: whereas he knew that what he did were only sham performances, and legerdemain tricks.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“But when they believed Philip - So it is evident that Philip's word came with greater power then that of Simon; and that his miracles stood the test in such a way as the feats of Simon could not.”
1871
A.D.
1871
“were baptized, both men and women--the detection of Simon's frauds helping to extend and deepen the effects of Philip's preaching.”

Undated

date unknown
date
unknown
Glossa Ordinaria Medieval
“By Philip. Some say that this Philip was an apostle, and one of the twelve, but it does not seem true according to the sequence of this book. Of Jesus Christ. Of whom they were ignorant, or (as has been said before) in the name of Jesus he preached the Trinity, and he who perfectly believes only one person of the Trinity cannot lack belief in the other two.”
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.