Gregory the Dialogist

And thou thoughtest thou wouldest not see darkness; and that thou wouldest not be borne down with the force of overflowing waters. As if he said in plain speech; 'Thou didst promise thyself security of peace in hope, and therefore thou wast glad for thine assurance as for the light, nor ever thoughtest for thyself to be oppressed with tribulation. …

Morals on the Book of Job, Book XVI ↗

Thomas Aquinas

He shows the reason why they come on him suddenly when he then says, "You thought that you would not see darkness," that is, you would not arrive at these doubts in which you do not know what to do, which refers to the snares. Then, as to the fear which throws him into confusion he says, "and you would not be oppressed by the force of flood waters," as if to say: You thought that you would never come to be oppressed by the violence and the great number of adversities coming from above, as 1 Thessalonians says, "When they say: peace …

Commentary on Job ↗