Rashi: It is in Yerushalayim. I saw what happened to Sancheriv, and then I realized that the end of Resha'im is to perish. I realized that all this good that they have, Hashem smoothes their path, so they will not put their hearts to repent to You, and they will perish.

Radak: It is the world of angels and Ruchos. There is the final lasting reward. The good of this world does not last. At the end, the world of Nefashos, in it will be distinguished the good and the evil.

Malbim: They are the places Kadosh to Hashem. In them, the Nefesh receives its reward and punishment after death.

Radak: Refer to 73:17:1:2.

Malbim: I realized that life in this world is not the end of man's life. Resha'im who succeed in their evil, this is the biggest punishment!