Job 17:5

He that speaketh flattery to his friends, even the eyes of his children shall fail.

Job 17:5 belongs to Job's reply to his three friends in their debate about his afflictions, in which he protests his innocence and expresses a desire for death. That debate between Job and his friends is arranged in three cycles of speeches. This reply forms part of his argument with them.

The verse warns that whoever speaks flattery to his friends brings harm that reaches even to his children. Not every statement made by the speakers in the book is true, and the friends often spoke things generally true but misapplied them to Job's suffering. It stands within Job 16-17 with no further explanation or application beyond that warning.