The interpretation timeline
Amos 8:5 Douay-Rheims

Saying: When will the month be over, and we shall sell our wares: and the sabbath, and we shall open the corn: that we may lessen the measure, and increase the sicle, and may convey in deceitful balances,

1105 – 1871 5 witnesses

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“Saying, “When will the month be delayed”—This is the swallowing up. They anticipate the time that the grain will be expensive and will be sold to the poor with interest, and they will take their fields. the month be delayed Heb. יַעֲבֹר. Jonathan renders: When will the year be interpolated and [when] will the month of interpolation come? This is an expression of delay, like (Jer. 46:17) “Has allowed the appointed time to pass by (הֶעֱבִיר).” And because they delay the offering up of the Omer, and the year is extended, and the old grain becomes expensive. and the Sabbatical Year, so that we will open grain—When will the Sabbatical Year come, and the grain will become expensive, and we will open our storehouses of grain. to make the ephah smaller To sell for a smaller measure, and our money we will receive with a large shekel.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Saying, when will the new moon be gone, that we may sell corn?.... The first day of every month, on which it was forbid to sell any thing, or do any worldly business, being appointed and used for religious service; see Kg2 4:23; and which these carnal earthly minded men were weary of, and wanted to have over, that they might be selling their grain, and getting money, which they preferred to the worship of God. Kimchi and Ben Melech interpret it of the month of harvest, when the poor found what to eat in the fields; when they gleaned there, and got a sufficiency of bread, and so had no need to buy corn; and hence these rich misers, that hoarded up the grain, are represented as wishing the harvest month over, that they might sell their grain to the poor, having had, during that month, no demand for it; and so the Targum renders it the month of grain: or the month of intercalation, as Jarchi understands it; every three years a month was intercalated, to bring their feasts right to the season of the year; and that year was a month longer than the rest, and made provision dearer; and then the sense is, when will the year of intercalation come, that we may have a better price for our grain? but the first sense seems best; and the sabbath, that we may set forth wheat; in the shops or markets, for sale: or "open wheat" (b); the granaries and treasures of it, to be seen and sold. Now the sabbath, or seventh day of the week, as no servile work was to be done on it, so no trade or commerce was to be carried on on that day; which made it a long and wearisome one to worldly men, who wished it over, that they might be about their worldly business. Kimchi and Ben Melech, by "sabbath", understand a "week", which these men put off the poor unto, when the price of grain would rise; and so from week to week refused to sell, and longed till the week came when it would be dearer. The Targum and Jarchi interpret it of the seventh year Sabbath, when there was no ploughing, nor sowing, nor reaping, and so no selling of grain, but the people lived upon what the earth brought forth of itself. But the first sense here is also best; making the ephah small; a dry measure, that held three scabs, or about a bushel of ours, with which they measured their grain and their wheat; so that, besides the exorbitant price they required, they did not give due measure: and the shekel great; that is, the weight, or shekel stone, with which they weighed the money the poor gave for their grain and wheat; this was made heavier than it should be, and so of course the money weighed against it was too light, and the poor were obliged to make it up with more; and thus they cheated them, both in their measure, and in their money: and falsifying the balances by deceit? contrary to the law in Deu 25:13. (b) "et apericmus frumentam", Pagninus, Montanus, Vatablus; "ut aperiamus frumenti horrea", Junius & Tremellius; "ut aperiamus frumentum", Piscator, Cocceius; "quo far aperiamus", Castalio.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“When will the new moon be gone - This was kept as a kind of holy day, not by Divine command, but by custom. The Sabbath was strictly holy; and yet so covetous were they that they grudged to give to God and their own souls this seventh portion of time! But bad and execrable as they were, they neither set forth their corn, nor their wheat, nor any other kind of merchandise, on the Sabbath. They were saints then, when compared to multitudes called Christians, who keep their shops either partially or entirely open on the Lord's day, and buy and sell without any scruples of conscience. Conscience! alas! they have none; it is seared as with a hot iron. The strong man armed, in them, is quiet, for all his goods are in peace. Making the ephah small, and the shekel great - Giving short measure, and taking full price; or, buying with a heavy weight, and selling with one that was light. Falsifying the balances - Having one scale light, and the other weighty; one end of the beam long, and the other short. A few months ago I detected a knave with such balances; with a slip of his finger along the beam he altered the center, which made three ounces short weight in every pound. He did it so dexterously, that though I knew he was cheating, or, as the prophet expresses it, was falsifying the balances by deceit, it was some time before I could detect the fraud, and not till I had been several times cheated by this accomplished knave. So we find that though the knaves of ancient Israel are dead, they have left their successors behind them.”
Source
1849
A.D.
1774–1849
“Month: the first day was observed as a festival, Numbers x. 10. (Haydock) — At the expiration of the month usurers demanded their money. (Horace, i. sat. 3.; Aristophanes, Nub. ii. 1.) — Corn, to sell after the sabbatical year, when it was dearest. Sabbath also denotes all “festivals.” These misers think that there are too many. — Sicle. Having a large measure to buy, and a small one to sell again, Deuteronomy xxv. 13., and Proverbs xx. 10.”
Source
1871
A.D.
1871
“So greedy are they of unjust gain that they cannot spare a single day, however sacred, from pursuing it. They are strangers to God and enemies to themselves, who love market days better than sabbath days; and they who have lost piety will not long keep honesty. The new-2moons (Num 10:10) and sabbaths were to be kept without working or trading (Neh 10:31). set forth wheat--literally, "open out" stores of wheat for sale. ephah--containing three seahs, or above three pecks. making . . . small--making it below the just weight to purchasers. shekel great--taking from purchasers a greater weight of money than was due. Shekels used to be weighed out in payments (Gen 23:16). Thus they committed a double fraud against the law (Deu 25:13-14).”
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.