יַכְּכָ֣ה יְ֠הוָה בַּשַּׁחֶ֨פֶת וּבַקַּדַּ֜חַת וּבַדַּלֶּ֗קֶת וּבַֽחַרְחֻר֙ וּבַחֶ֔רֶב וּבַשִּׁדָּפ֖וֹן וּבַיֵּרָק֑וֹן וּרְדָפ֖וּךָ עַ֥ד אָבְדֶֽךָ׃
גאָט װעט דיך פּלאָגן מיט דער, און מיט קדחת, און מיט היץ, און מיט ברענונג, און מיט טריקעניש, און מיט קאָרנבראַנד, און מיט װעלקעניש; און זײ װעלן דיך נאָכיאָגן ביז דו װעסט אונטערגײן.
Siftei Chakhamim
Hasledes in O.F. Rashi [is answering the question:] שידפון is a type of disease, affecting only people, not grain. [So why does it say שדופות]? He answers: In O.F., [afflicted grain] is called hasledes, even though this is a human disease. And so it is in Hebrew. Whereas Onkelos does not translate שדופות as שידפון, but as שקיפן, which means “beaten.” So explains Re’m. But Maharshal writes about this: To me it does not seem so, because in Devarim 28:22 Rashi clearly explains that שידפון is an epidemic affecting grain. It must be that שידפון and שדופות are different, for Rashi cites a different O.F. word here than he does there. And we cannot say that here Rashi is explaining [it in connection with] the wind, because Rashi there explains differently in connection with the wind.
Ibn Ezra
Confusion means, you will be confused and will not know what to do (although some say that confusion means “suddenly”). Many people have drawn the conclusion, without cause, that shaḥefet and qaddaḥat are both plant diseases (similar to “blasting” and “mildew” [Deuteronomy 28:22], which are known from Scriptural context [Amos 4:9] to be plant diseases), on account of the phrase you will sow in vain . The actual meaning is that they will contract illnesses; then, when enemies come to their villages and eat their grain, no one will be able to go out against them and drive them away.
Bekhor Shor
And you shall not defraud, each one their kin To sell according to the worth of the land, since it will return. Although there is no concept of fraud with regard to land (cf Sifra Behar 3:1), here there is fraud, since one does not acquire land in Eretz Yisrael but rather only its products, like the verse says "For the number of years they sell to you" (Leviticus 25:15). If it had been years like the years of Eliyahu (ie of drought, cf I Kings 17:1), or blasting and mildew (cf Devarim 28:22), one would not decrease the account of the money if the redeemer came to redeem. And so too the two years that the Sages said one needs to leave the land in their hand, they need to be productive years.
Rashi
והיו שמיך אשר על ראשך נחשת AND THY HEAVEN WHICH IS OVER THY HEAD SHALL BE COPPER — These curses (i.e. all the curses contained in this chapter) Moses expressed them as though they came from his own mouth (Megillah 31b) whilst those he spoke on Mount Sinai (Leviticus 26), he expressed them as though from the mouth of the Holy One, blessed be He, as indeed is implied by them (by the expressions used), for so it states there: “And if ye will not hearken unto Me”; “And if ye walk contrary to Me”, whilst here it says: “[And if thou wilt not obey] the voice of the Lord thy God”; “The Lord shall make cleave unto thee”; “The Lord shall smite thee”. Moses was milder in his curses, expressing them in the singular (“The Lord shall smite thee”, not “you”, the entire people), and similarly in this curse, too, he was milder, for in the former curses (those in Leviticus) it states, (Leviticus 26:19) “[I will make] your heaven as iron and your earth as copper”, i.e., that the heaven would not exude moisture, just as iron does not exude, and there would therefore be drought in the world, whilst the earth would exude moisture (be humid) just as copper sweats, and it would consequently rot the fruits. Here, however, it states, “Thy heaven shall be copper and thy earth shall be iron”, i.e. that the heavens would exude moisture: even though they might not pour with rain, at any rate there would be no ruinous drought in the world; whilst the earth would not exude moisture just as iron does not sweat, and consequently the fruits would not perish. Nevertheless this is a curse: for whether it (the earth) be as copper or whether it be as iron it will produce no fruit, and the heaven, too, will not pour with rain (give rain in abundance) (cf. Sifra, Bechukotai, Chapter 5 3 on Leviticus 26:19).