"And the Satan standing at his right to prosecute him"
The negative angel, Satan, stands on the right side of the High Priest Joshua, who has just been thrown into a pit of fire. Kabbalistically, the right side signifies the attribute of mercy, and fire signifies the concept of severe judgment. In this story, the angel Satan tells the Creator that if He is going to show mercy upon Joshua, then He should be obligated to save all the people who were with Joshua, even though they are unworthy. In other words, Satan is cleverly implying that the Creator cannot possibly save Joshua because of these special circumstances. Nonetheless, the Creator emancipates Joshua. The spiritual lesson of this story is as follows, During a time of intense judgment, the righteous can still be saved amidst all the upheaval and destruction. According to the Kabbalah, another example of the Creator performing the difficult task of concurrently emitting the forces of mercy and judgment, was during the splitting of the Red Sea, when the Israelites crossed over to safety while the Egyptians were drowning.
Both wicked and righteous people dwell among us and their behavioral actions have a corresponding effect on the state of the world. By mending our own ways and choosing the path of spirituality, we are securely connected, by this section, to the Creator's attributes of mercy during times of severe judgment.