The sons of Kirach did not fall into the abyss that had opened under their feet, but landed on a ledge in the ground that had miraculously appeared for them. Being in such a « suspended » state and also after having climbed up, they saw things which are not always accessible to human understanding, and prophesied.
Some of these prophecies were included by King David in the book of Tehilim. Chapters 42 and 43, which we usually read every 8th day of the Hebrew months, are two of these prophetic songs.
Chapter 42 describes how a person who finds himself in galut (exile) is longing to return to haShem. The song is written in first person to show: anyone who lives through the time of exile can say the same.
Commentators note that during the Babylonian exile (which is prophetically mentioned in this song) this song was especially popular among the descendants of the Korach’s sons – the Levites.