Jamieson, Fausset and Brown on Job 7:12

12. Why dost thou deny me the comfort of care-assuaging sleep? Why scarest thou me with frightful dreams?

Am I a sea--regarded in Old Testament poetry as a violent rebel against God, the Lord of nature, who therefore curbs his violence (Jr 5:22).

or a whale--or some other sea monster (Is 27:1), that Thou needest thus to watch and curb me? The Egyptians watched the crocodile most carefully to prevent its doing mischief.