The interpretation timeline
Acts 6:15 Douay-Rheims

And all that sat in the council, looking on him, saw his face as if it had been the face of an angel.

A.D. 220 – 1871 6 witnesses

Patristic

before A.D. 750
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“But he was Moses still, even when he was not visible. So also Stephen had already put on the appearance of an angel, although they were none other than his human knees which bent beneath the stoning.”
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“"And all that sat in the council, looking steadfastly on him, saw his face as it had been the face of an angel." So possible is it even for one in a lower degree to shine. For what, I ask, had this man less than the Apostles? He lacked not miracles, and great was the boldness he exhibited. "They saw His face," it is said, "as it had been the face of an angel." For this was his grace, this was the glory of Moses. God made him thus gracious of visage, now that he was about to say somewhat, thus at once by his very look to awe them. For there are, yes, there are faces full-fraught with spiritual grace, lovely to them that love, awful to haters and enemies. It mentions also the reason, why they suffered his oration. But to show that it was not in the nature of such a man to speak such things, and harshly, "Then all," it says, "which were in the council, looking steadfastly upon him, saw his face, as it had been the face of an angel": so mild was he even in countenance. For, in cases where persons were not falsely accused, Scripture mentions nothing of this kind: but as in this case it was all false accusation, with reason does God rectify it by the very look of the man. For the Apostles indeed were not falsely accused, but were forbidden: but this man is falsely accused: and therefore before all else his countenance pleads for him. This abashed even the priest. "They saw his face as it had been the face of an angel." "Full of faith and of power": which is also the character given of Barnabas "he was a good man, full of faith and of the Holy Ghost." Whence we learn that the sincere and innocent are, above all others, the men to be saved, and that these same are also more gracious.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And all that sat in the council,.... The whole sanhedrim, looking steadfastly on him; to observe whether his countenance altered, his tongue stammered, or he trembled in any part of his body, neither of which appeared; but on the contrary, they saw his face, as if it had been the face of an angel. The Ethiopic version adds, "of God"; there was such a calmness and serenity in it, which showed his innocence and unconsciousness of guilt; and such a beauty and glory upon it, that he looked as lovely and amiable as the angels of God, who when they appeared to men, it was in very glorious and splendid forms: his face might shine as Moses's did, when he came down from the mount; or in some degree as Christ's did at his transfiguration; and this might, as it ought to have been, taken as an acquittance of him by God, from the charge of blasphemy, either against God or Moses: the Jews (q) say of Phinehas, that when the Holy Ghost was upon him, his face burned or shone like lamps, and Stephen was now full of the Holy Ghost, Act 6:5. (q) Ceseph. Misna in Maimon. Hilch. Teshuba, c. 9. & Vajikra Rabba, sect. 1. fol. 146. 1. & sect. 21. fol. 163. 1. Next: Acts Chapter 7”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Saw his face, as it had been the face of an angel - Sayings like this are frequent among the Jewish writers, who represent God as distinguishing eminent men by causing a glory to shine from their faces. Rabbi Gedalia said that, "when Moses and Aaron came before Pharaoh, they appeared like those angels which minister before the face of the Lord; for their stature appeared greater, and the splendor of their faces was like the sun, and their eyes like the wheels of the sun; their beard like clusters of grapes, and their words like thunder and lightning; and that, through fear of them, those who were present fell to the earth." The like is said of Moses, in Debarim Rabba, fol. 75. that "when Sammael (Satan) came to Moses, the splendor of his face was like the sun, and himself resembled an angel of God." The reader may find several similar sayings in Schoettgen. It appears that the light and power of God which dwelt in his soul shone through his face, and God gave them this proof of the falsity of the testimony which was now before them; for, as the face of Stephen now shone as the face of Moses did when he came down from the mount, it was the fullest proof that he had not spoken blasphemous words either against Moses or God, else this splendor of heaven had not rested upon him. The history of the apostolic Church is a series of wonders. Every thing that could prevent such a Church from being established, or could overthrow it when established, is brought to bear against it. The instruments employed in its erection and defense had neither might nor power, but what came immediately from God. They work, and God works with them; the Church is founded and built up; and its adversaries, with every advantage in their favor, cannot overthrow it. Is it possible to look at this, without seeing the mighty hand of God in the whole? He permits devils and wicked men to work - to avail themselves of all their advantages, yet counterworks all their plots and designs, turns their weapons against themselves, and promotes his cause by the very means that were used to destroy it. How true is the saying, There is neither might nor counsel against the Lord!”
Source
1849
A.D.
1774–1849
“Saw his face, as it were the face of an angel. All in the council, or sanhedrim, saw an extraordinary and charming brightness in the countenance of Stephen, which struck them with admiration and fear. (Witham) — Angel. His face shone with a wonderful brightness, an emblem of his interior perfection. In this he was like Moses, whose countenance was so bright, that the Jews could not steadfastly behold it. By this the beholders had an opportunity of being converted, had they so wished, or were rendered inexcusable for their neglect. It is also a testimony of the great sanctity of the deacon. This same miracle is not recorded to have happened to any other but Moses, and our Lord at his transfiguration. (Denis the Carthusian) — Although this appearance, in an inferior degree, has been not unfrequently observed in the constant and cheerful countenance of the martyrs before their persecutors, and of privileged saints, whilst they were happily employed in their intimate communications with heaven.”
Source
1871
A.D.
1871
“as . . . the face of an angel--a play of supernatural radiance attesting to all who beheld his countenance the divine calm of the spirit within. Next: Acts Chapter 7”
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.