Job 15:4 - Ellicott's Commentary On The Whole Bible

Yea, thou castest off fear. — The tendency also of Job has been to encourage a kind of fatalism (e.g., Job 12:16-25), and therefore to check the offering of prayer to God, besides setting an example which, if followed, as from Job’s position it was likely to be, would lead to murmuring and blasphemy.