How is the curse issued?
Bava Metzia 48b
Abbaye said: We inform him [of the danger]. Rava said: We curse him. Abbaye said we only inform him, for it is written, "Do not curse a leader in your nation." Rava said we curse him, for "in your nation" means one who acts like your nation.
Rambam, Mishneh Torah, Laws of Sales 7:2
We curse him in the court and say, "The One who punished the generation of the flood, the generation of the dispersion, the citizens of Sdom and Amorah, and Egypt who drowned at the sea, will also punish one who does not stand by his word." Then the money is returned.
R' Yechiel Michel Epstein, Aruch haShulchan Choshen Mishpat 204:2
Some say that the chazan declares this publicly in the synagogue, but that is not the practice. We also don't curse him directly; the court curses him in the courthouse, whether there is a large group present or not.
How are we to understand the mi shepara’s association with these four groups of people that were punished?
(the generation of the flood, the generation of the dispersion, the citizens of Sdom and Amorah, and Egypt at the sea)
Aruch haNer (Succah 52): these four generations were punished by a method representative of the upsetting the desire order of the four Yesodos of the world. Water is represented by the Dor haMabul; Dor haPlagah represents wind; Sdom and Amorah represent fire; and the Egyptians at the sea were sunk in the mud representing earth.
The Tifferes Yisrael explains that there are four reasons why people sin; they are represented by these four groups. The first is desire to satisfy physical or material desires. Even though the generation of the flood was ultimately punished for their thievery, they were a generation that was consumed by the pursuit of physical pleasures. The Torah highlights not just thievery but they pursuit of woman, etc. The second reason for sin is the pursuit of honour. “Let us make for ourselves a name” was the battle cry of the generation of the dispersion. The third is the insatiable appetite for money. The people of Sedom were famous for guarding their wealth and being in opposition to helping those in need. The final reason is the denial of HaShem’s providence. This was the sin of Paro how said, “who is HaShem?” and persisted in his sin. He believed that there was no ultimate Overseer and that man-kind was like fish in a trap where the strong dominate the weak and the fittest survives.
These four groups broke down their society and were punished in kind. Similarly, a person who does not keep his word, motivated by one of these four reasons, breeds distrust and create fractures in society. Therefore, the curse, his actions motivated by one of these four reasons, is associated with these four groups.
