Job 41:31

He maketh the deep to boil like a pot - In his rapid motion through it. The word “deep” (מצולה m^etsôlâh) may refer to any deep place - either of the sea, of a river, or of mire, Psalms 69:2. It is applied to the depths of the sea, Jonah 2:3; Micah 7:19; but there is nothing in the word that will prevent its application to a large river like the Nile - the usual abode of the crocodile.

He maketh the sea - The word “sea” (ים yâm) is often applied to a large river, like the Nile or the Euphrates; see the notes at Isaiah 19:5.

Like a pot of ointment - When it is mixed, or stirred together. Bochart supposes that there is an allusion here to the smell of musk, which it is said the crocodile has, and by which the waters through which he passes seem to be perfumed. But the allusion seems rather to be merely to the fact that the deep is agitated by him when he passes through it, as if it were stirred from the bottom like a pot of ointment.