John Calvin Commentary Genesis 39:10

"And it came to pass, as she spake to Joseph day by day, that he hearkened not unto her, to lie by her, [or] to be with her." — Genesis 39:10 (ASV)

As she spake to Joseph day by day. Joseph's constancy is commended; from this, it appears that a real fear of God reigned in his mind. Thus it came about that he not only repelled one attack but stood firm, until the end, as the conqueror of all temptations.

We know how easy it is to fall when Satan tempts us through another: because we seem exempt from blame if the one who induces us to commit the crime bears a part of it. Holy Joseph, therefore, must have been endowed with the extraordinary power of the Spirit, since he stood invincible until the end against all the allurements of the impious woman.

All the more detestable is her wickedness, as she is neither corrected by time nor restrained by many repulses. When she sees a stranger, and one who had been sold as a slave, so discreet and so faithful to his master, and when she is also solemnly admonished by him not to provoke God's anger, how indomitable is that lust which leaves no room for shame.

Now, because we see here what evils people will rush into when regard for propriety is extinguished by carnal intemperance, we must entreat the Lord that He will not allow the light of His Spirit to be quenched within us.