Genesis 39

7. his master's wife cast her eyes upon Joseph--Egyptian women were not kept in the same secluded manner as females are in most Oriental countries now. They were treated in a manner more worthy of a civilized people--in fact, enjoyed much freedom both at home and abroad. Hence Potiphar's wife had constant opportunity of meeting Joseph. But the ancient women of Egypt were very loose in their morals. Intrigues and intemperance were vices very prevalent among the them, as the monuments too plainly attest [WILKINSON]. Potiphar's wife was probably not worse than many of the same rank, and her infamous advances made to Joseph arose from her superiority of station.

9. How then can I do this great wickedness, and sin against God?--This remonstrance, when all inferior arguments had failed, embodied the true principle of moral purity--a principle always sufficient where it exists, and alone sufficient.

14. Then she called unto the men of her house--Disappointed and affronted, she vowed revenge and accused Joseph, first to the servants of the house, and on his return to her lord.
See, he hath brought in an Hebrew . . . to mock us--an affected and blind aspersion of her husband for keeping in his house an Hebrew, the very abomination of Egyptians.

20. Joseph's master took him, and put him into the prison--the roundhouse, from the form of its construction, usually attached to the dwelling of such an officer as Potiphar. It was partly a subterranean dungeon ( Genesis 41:14 ), though the brick-built walls rose considerably above the surface of the ground, and were surmounted by a vaulted roof somewhat in the form of an inverted bowl. Into such a dungeon Potiphar, in the first ebullition of rage, threw Joseph and ordered him to be subjected further to as great harshness of treatment ( Psalms 105:18 ) as he dared; for the power of masters over their slaves was very properly restrained by law, and the murder of a slave was a capital crime.
a place where the king's prisoners were bound--Though prisons seem to have been an inseparable appendage of the palaces, this was not a common jail--it was the receptacle of state criminals; and, therefore, it may be presumed that more than ordinary strictness and vigilance were exercised over the prisoners. In general, however, the Egyptian, like other Oriental prisons, were used solely for the purposes of detention. Accused persons were cast into them until the charges against them could be investigated; and though the jailer was responsible for the appearance of those placed under his custody, yet, provided they were produced when called, he was never interrogated as to the way in which he had kept them.

21-23. The Lord . . . gave him favour in the sight of the keeper of the prison, &c.--It is highly probable, from the situation of this prison ( Genesis 40:3 ), that the keeper might have been previously acquainted with Joseph and have had access to know his innocence of the crime laid to his charge, as well as with all the high integrity of his character. That may partly account for his showing so much kindness and confidence to his prisoner. But there was a higher influence at work; for "the Lord was with Joseph, and that which he did, the Lord made it to prosper."