פרשת וישב



לז,כו וַיֹּאמֶר יְהוּדָה, אֶל-אֶחָיו:  מַה-בֶּצַע, כִּי 
נַהֲרֹג אֶת-אָחִינוּ, וְכִסִּינוּ, אֶת-דָּמוֹ

לז,כז לְכוּ וְנִמְכְּרֶנּוּ לַיִּשְׁמְעֵאלִים, וְיָדֵנוּ אַל-תְּהִי-בוֹ, כִּי-אָחִינוּ בְשָׂרֵנוּ, הוּא; וַיִּשְׁמְעוּ, אֶחָיו.

לז,כח וַיַּעַבְרוּ אֲנָשִׁים מִדְיָנִים סֹחֲרִים, וַיִּמְשְׁכוּ וַיַּעֲלוּ אֶת-יוֹסֵף מִן-הַבּוֹר, וַיִּמְכְּרוּ אֶת-יוֹסֵף לַיִּשְׁמְעֵאלִים, בְּעֶשְׂרִים כָּסֶף; וַיָּבִיאוּ אֶת-יוֹסֵף, מִצְרָיְמָה.

The question everyone discusses here is why the switch between ישמעאלים and  

 מדינים?                                                          

                                                     

 I don't believe that the question is so difficult. It is very common in the slave trade to have slave traders that arrange the sale for buyers. When יהודה decided to sell יוסף to the Egyptians, it was the midyanim that were the traders and     arranged and completed the sale to the Egyptians.                                                  
 What I find fascinating is the fact that the two people chosen in this story to arrange the sale of Joseph, were the very same children that were sent away by Joseph's great grandfather Abraham; and now the very descendants of those children are now involved in sending Joseph away from his father.