Sforno on Genesis 37:28/ספורנו על בראשית ל״ז:כ״ח

1מדינים סוחרים, the owners of the merchandise being transported on the Ishmaelites’ camels.

2וימכרו את יוסף לישמעאלים, they completed the deal with the Ishmaelites acting as agents for the Midianites. The brothers did not want to speak to the Midianite merchants. The reason was that they did not want to be recognised by them as they were in the habit of frequenting cities in order to ply their wares. The camel drovers, however, were not in the habit of visiting urban areas. At worst they would just pass through towns without stopping there overnight or longer. The actual purchasers, however, were the Midianite merchants, in accordance with the Torah’s narrative that the Midianites sold Joseph to Egypt (verse 36). The Jewish people experienced something parallel during the period of the second Temple, when Midianites sold a portion of our people into slavery to surrounding nations, a phenomenon which was widespread during the time when the descendants of the Hasmoneans were fighting among themselves about who would be king in Jerusalem. This fratricide is responsible for our exile until this day. It was a historical replay of what happened as a result of the brothers selling Joseph, and the whole family winding up in exile in Egypt only a few years later. Compare what our sages have to say on the subject in Shabbat 10.