Genesis 39:1

"And Joseph was brought down to Egypt; and Potiphar, an officer of Pharaoh's, the captain of the guard, an Egyptian, bought him of the hand of the Ismaelites, that had brought him down thither."

This important verse does a number of things:

1. It shows that the Ismaelites and Midianites of Genesis 37 were the same group of traders.
   
2. It gives more fully the status of Potiphar, captain of the guard, an office that also included the directorship of the prisons, the deputy of Potiphar also being called, the captain of the guard, the title relating to his actual work. It is clear that he held his authority under Potiphar (Genesis 40:3). In fact, Potiphar may actually be the one referred to in that verse.
   
3. The race of Potiphar is also given as Egyptian, an essential note, for, if this was during the Hyksos kings of Egypt, the employment of Egyptians who were of a different race was unusual, and may also explain why Potiphar was a eunuch. We have already noted that the word could have meant merely a king's officer, but the possibility remains that he was actually a eunuch. If so, it would explain his wife's inordinate desire to seduce Joseph. Morris elaborated this thesis rather fully as follows:
   

"It was a custom in ancient pagan countries, beginning with Sumeria, to require prominent officers associated closely with the king's court to be castrated, in order to minimize the possibility of their taking over the kingdom and founding their own dynasty. Here it seems that either Potiphar (already married) had consented to be castrated in order to hold the office, or that his wife, after the event, married him for financial or political reasons. Some eunuchs were known to have wives."[4]

Naturally, the information contained in this verse refutes many of the claims of critical Biblical enemies; so what do they do with it? They throw it out of the Bible! A portion of this verse was explained by Speiser as a "redactorial gloss!"[5] Of course, it is no such thing. "It is just another of the guesses of criticism."[6]