Why are a cloud and darkness around Him?
Radak: They are to darken on the Resha'im.
Malbim: The verse depicts that they hide Hashgachah; it is not recognized at all. Many think that the Ma'arachah conducts the world via nature, and this is inevitable.
Why does it say "Tzedek u'Mishpat Mechon Kis'o"?
Radak: Then, they will recognize that His throne is based on Tzedek and Mishpat. Now, due to the success of Resha'im, they think that there is no Mishpat.
Malbim: Even though the supreme Conductor and His Hashgachah are hidden, Shamayim's conduct, which is called Hashem's Kisei - "Hashem ba'Shamayim Hechin Kis'o" (103:19), the base of this Kisei is arranged based on laws of Tzedek and Mishpat, and reward and punishment based on the generation's deeds.
