Genesis 37:28

"And Midianite men passed by". This refers to a diferent caravan, and [therefore] the verse is informing you that he was sold multiple times.

"and they pulled". The sons of Jacob [pulled] Joseph from the pit and sold him to Ishmaelites, and the Ishmaelites [sold him] to the Midianites, and the Midianites [sold him] to the Egyptians.

And the Midianite men, masters of business, passed by; and they drew and brought up Joseph out of the pit, and sold Joseph to the Arabians for twenty mahin of silver; and they bought sandals of them. And they brought Joseph to Mizraim.

When the Ishmaelite merchants passed by them, because the Midianites are called Ishmaelites. And so it says about the kings of Midian, that they were Ishmaelites (Shoftim 8:24).

ויעברו אנשים מדינים, while the brothers had been sitting down to consume their meal, having distanced themselves somewhat from the pit into which they had thrown Joseph in order not to be guilty of “eating while spilling blood,” they were waiting for the Ishmaelites whom they had seen in the distance, to arrive. During this period the Midianites, coming from a different direction had passed there, saw Joseph in the pit, pulled him up, and proceeded to sell him to the Ishmaelites. One may assume that the brothers had no knowledge of this. Even though the Torah appears to attribute the sale of Joseph to the Ishmaelites to the brothers, (based on Joseph accusing them of having sold him to Egypt, 45,4) we would have to say that because of their having been instrumental in bringing about that sale they are considered as if having assisted in that sale. This appears to me the deeper meaning of the plain meaning of the text both here and in chapter 45. The line describing the Midianites passing that way is described as something totally coincidental, having nothing to do with what the brothers had planned to do with Joseph. Even if the Torah says:וימכרו (את) יוסף לישמעאלים, this sounds as if the brothers did the selling. It is also possible that the brothers noting the Midianites suddenly materialising out of nowhere, instructed them to pull Joseph out of the pit after which they themselves sold him to the Ishmaelites.

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

וימכרו 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.

ויעברו אנשים מדינים, these were the Ishmaelites mentioned previously, seeing that both Midianites and Medanites are descendants of Keturah. [Keturah is understood to be Hagar who had her name changed after Sarah’s death when Avraham took her as a wife. Seeing that she gave birth to both Medan and to Midian, (25,2) this made both these sons full brothers to her earlier son Ishmael by the same father. Ed.] Even assuming that Keturah and Hagar were not identical, the three were at least sons of Avraham and therefore half brothers. Their respective families had intermarried so that they could be considered as brothers in the real sense of the word. The close relationship between their respective descendants comes to the fore in Judges 8,24 where after Gideon’s campaign against the Midianites they are described as Ishmaelites, the kind of jewelry they wore identifying them as members of that tribe.

וימשכו, Joseph’s brothers pulled him out of the pit prior to the sale to the Ishmaelites. All this occurred when Reuven was not present. Perhaps, in the interval he had returned to his father. [a distance of 120 km, hardly likely, as Reuven would have had to come back another 120 km. to retrieve Joseph who would have died from thirst in the interval if not from other causes. Ed.] It is more likely that Reuven had a flock of his own to look after in that general region.

וימשכו ויעלו, “they pulled and raised;” first they struck a deal to sell him for twenty pieces of silver. Then in order to deliver him to the purchaser they had to haul him out of the pit. While Joseph had been in the pit, wondering how he would ever escape, he had lost his good looks and was not presentable to people who wished to buy a young and able bodied slave. As soon as he was hauled out of the pit he regained his former looks. The sellers were now not prepared to sell him for so little money and they were about to throw him back into the pit. In order to prevent this, the Ishmaelites added shoes of their own free will in order to satisfy the Midianite merchants. This is what the prophet Amos referred to (Amos 2,6) when he said: על מכרם בכסף צדיק ואביון בעבור נעלים, “because they have sold for silver those whose cause was just and the needy for a pair of sandals.” As soon as the Ishmaelites offered more than originally, the Midianites raised Joseph from the pit again.