Genesis 37:25

And they sat around to eat bread. And they lifted up their eyes, and looked, and behold a band of Arabians were coming from Gilead with their camels, carrying wax, resin, balsam and stacte, proceeding to go into Mizraim.

AND, BEHOLD, A CARAVAN OF ISHMAELITES CAME FROM GILEAD. When they looked up and saw at a distance men approaching from the direction of Gilead,), and finally as Midianites (Verse 36). they recognized them as a camel caravan of Ishmaelites on their way to Egypt, for it was from Gilead that balms and spices came, and it was their custom to bring it to Egypt. This was why Judah said to them, “Behold these men come from afar and are travelling to a distant country. Let us sell him to them so that the matter should not become known.” And when they came near they discovered them to be merchants of spices and balms — Midianites, merchantmen — who had hired the camels from the Ishmaelites. They sold Joseph to the Midianites who purchased him for profit, but the company of Ishmaelites, the lessors of the camels, would not purchase him for their own investment purposes. The verse which states, And they sold Joseph to the Ishmaelites, means that it was to them that the Midianites who bought him turned him over, for they were the ones who transported the merchandise to Egypt. This is also the meaning of the verse, From the hand of the Ishmaelites, that had brought him down thither, for he was in their care. But the Midianites were his masters, and they made trade with him. This is the sense of the verse, And the Midianites sold him to Egypt.
All stories in Scripture are written in this manner: sometimes it is told in the name of the authority who commands that it be done, and other times in the name of the agent who performs the act. Such a case is the verse, All the great work of the Eternal which He did, while elsewhere it states, Which Moses did in the sight of all Israel., 34:12. Similarly it says, Thus all the work that king Solomon did in the house of the Eternal was finished, but it was Hiram that did it, as it is written, And he came to king Solomon, and wrought all his work., Verse 14. In the case of Joseph himself, the verse says, And whatsoever they did there, he was the doer of it, thus ascribing the action both to he who commanded it and the one who did it.
Rabbi Abraham ibn Ezra says that the Midianites are called Ishmaelites, just as Scripture, in speaking of Midianite kings, says, Because they were Ishmaelites. But the matter is not as Ibn Ezra considered it to be since the verse which states, For they had golden ear-rings, because they were Ishmaelites, alludes to “the children of the east” whose war it was, as it is written, Now all the Midianites and Amalekites and the children of the east assembled themselves together,, 6:33. and “the children of the east” are Ishmaelites, for concerning all the sons of the concubines that Abraham had, it is said, And he sent them away from Isaac his son, while he yet lived, eastward, unto the east country. It is also possible that the kings were Ishmaelites who ruled over Midian. Otherwise, why should “kings of Midian” be called by the name of Ishmael their brother?
In line with the literal sense of Scripture the correct interpretation concerning the sale of Joseph is as we have said. But our Rabbis have said that he was sold several times [and have thereby explained why his captors are alternately referred to as Midianites and Ishmaelites].

וישבו לאכול לחם, to demonstrate that what they had done was no crime in their eyes, or that the incident was not something that should interfere with their regular meal. When righteous people become aware of having inadvertently committed a sin, they not only do not celebrate it by eating, but they impose a fast day or more upon themselves. A prominent example of people imposing a fast day upon themselves, although they did not feel guilty for having done something wrong, were the Jewish tribes after having practically wiped out the tribe of Binyamin. We read about this in Judges 21,2-3 as well as about the fact that they imposed a fast upon themselves in spite of being convinced that they had done the right thing in going to war against that tribe. We also find something parallel when the King Darius threw Daniel into a pit full of starving lions. (Daniel 6,19). [The King had acted in accordance with the constitution of his country which demanded that a “heretic” such as Daniel be thrown to the lions, and the king’s efforts to have the law changed were rejected by his advisers. In spite of being legally correct, the king felt so badly that he went to bed hungry as a kind of penance for doing what was legally correct. Ed.] If the brothers sat down to eat immediately after throwing Joseph into the pit, this is clear evidence that in their minds they had certainly not committed any wrong. WE, who were not part of Yaakov’s household, and who know that these brothers were unanimously elevated to become the founding fathers of the Jewish nation, must therefore accept the premise underlying their actions as being that they had truly felt themselves personally threatened by Joseph, someone who was considered so mature that his own father had appointed him as manager over his senior brothers. The brothers had made strenuous efforts to put physical distance between themselves and Joseph in order to avoid any altercation. When he had sought them out in spite of their having signaled clearly that they wanted to avoid him, they felt understandably very threatened.

הולכים להוריד מצרימה, these Ishmaelites were camel owners, they did not own the merchandise described which was carried by their camels. As soon as they would deliver the merchandise to the appropriate address in Egypt their mission was completed.

נכאת, according to Bereshit Rabbah 91,11, wax.

צרי, according to the view of Rabbi Shimon ben Gamliel the word refers to resin, sap found in the trunk of the balsam tree. The word לוט according to Bereshit Rabbah 91,11 is מצטכי, Lotus?.