The interpretation timeline
Leviticus 23:27 Douay-Rheims

Upon the tenth day of this seventh month shall be the day of atonement, it shall be most solemn, and shall be called holy: and you shall afflict your souls on that day, and shall offer a holocaust to the Lord.

1105 – 1871 5 witnesses

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
אך — The words אך and רק wherever they occur in Scripture have a limitative force; here the word implies: it (Yom Kippur) makes expiation for those who repent, but it does not make expiation for those who do not repent (אך... יום הכפורים הוא — in a limitative sense it is Yom Kippur) (Shevuot 13a; cf. Rashi on Exodus 34:7).”
Source
1270
A.D.
Ramban Jewish
1194–1270
“ACH’ (BUT) ON THE TENTH DAY OF THIS SEVENTH MONTH IS THE DAY OF ATONEMENT. “All expressions in the Torah of ach (but) and rak (only) indicate limiting qualifications, [and here the word ach indicates that the Day of Atonement] effects atonement ‘only’ for those who repent, but it does not effect atonement for those who do not repent.” This is Rashi’s language on the basis of the words of our Rabbis. And if so, the explanation of the verse is that on the first day of this month [Tishri] there will be for all of you a day of memorial of ‘t’ruah [a blowing of the quavering sound which signifies judgment], for you will all be judged then before Him, but for some of you [i.e., those who repent] there will be on the tenth day of this month a day of atonement. Thus the meaning of the word ach is like that of bilvad (“only,” “alone”). Similarly, Now therefore forgive, I pray thee, my son ‘ach’ (only) this once. So also, ‘harak ach b’Moshe’ means “has He indeed spoken ‘only’ with Moses?” Likewise, ‘Ach’ on the fifteenth day of the seventh month means “only on the fifteenth day [of Tishri] ye shall keep the feast of the Eternal seven days, not consecutively,” for the Festival-offering [brought by the individual] does not override the Sabbath [and therefore it cannot mean seven days consecutively]. In the same way you are to explain [the word ach] in all the commandments, in accordance with the tradition of our Rabbis. Similarly, ‘ach’ he is torn in pieces means [that Jacob said] that nothing else [could have happened to Joseph] except that he was torn in pieces. So also, For the children of Israel and the children of Judah ‘ach’ have done that which was evil in My sight from their youth; for the children of Israel have ‘ach’ provoked Me, means that they have done nothing else. But by way of the plain meaning of Scripture the word ach means achein (“surely”), [a word which is used] to authenticate something, [as in the following expressions]: ‘achein’ (surely) the thing is known; ‘achein’ (surely) ye shall die like men. And here it means, “Surely on the tenth day of the seventh month is the day of atonement,” the expression constituting a [Divine] assurance on the authenticity of the matter, Scripture stating: “On the first day of the month is the day of judgment, but indeed on the tenth of the month is the day of atonement, therefore you shall afflict your souls, and you shall do no manner of work.” Similarly, ‘ach’ (surely) thou art my bone and my flesh; ‘ach’ (surely) it is the king of Israel; ‘ach’ (surely) G-d is good to Israel, even to such as are pure in heart. So also is the meaning of the verse, ‘ach’ ye shall keep My Sabbaths which declares: “Now I have commanded you concerning the work of the Tabernacle, but surely My Sabbaths you shall keep forever.” So also in all cases [where the word ach is mentioned] it may be explained to you in this way, if you will understand them.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Also on the tenth day of this seventh month,.... Tisri, the same as before, answering to part of our September, and part of October: there shall be a day of atonement; for all the sins of the year past; see Lev 16:29, it shall be an holy convocation unto you: when they should be called together for the exercise of holy duties: and ye shall afflict your souls; their souls, by repentance, contrition, and humiliation for sin, and their bodies by fasting; and, as the Targum of Jonathan paraphrases it,"by abstaining from eating and drinking, and the advantage of bathing and wiping, and the use of the bed and sandals;''hence called the fast, Act 27:9; See Gill on Lev 16:29, and offer an offering made by fire unto the Lord; a burnt offering, of which see Num 29:8.”
Source
1863
A.D.
1796–1863
“Supra 19 : 9, 12. H. P. They shall be holy to the Lord for his use." M H. P. "Thou shalt not make clean riddance of the oorners of thy field when thou reapest." u The precise object commemorated is not known. The Divine benefits in general may hare been celebrated. The feast fell in the month of Tlsri, corresponding to September. Nnmb. 29 : 1. The end to which it was directed was to appease God offended by sin.”
Source
1871
A.D.
1871
“there shall be a day of atonement . . . and ye shall afflict your souls--an unusual festival, at which the sins of the whole year were expiated. (See Lev 16:29-34). It is here only stated that the severest penalty was incurred by the violation of this day.”
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.