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

(f) He who flatters a man, and only judges him happy in his prosperity, will not himself only but in his posterity be punished.

Jamieson-Fausset-Brown Bible Commentary

5. The Hebrew for "flattery" is "smoothness"; then it came to mean a prey divided by lot, because a smooth stone was used in casting the lots (De 18:8), "a portion" (Ge 14:24). Therefore translate, "He that delivers up his friend as a prey (which the conduct of my friends implies that they would do), even the eyes," &c. [Noyes] (Job 11:20). Job says this as to the sinner's children, retorting upon their reproach as to the cutting off of his (Job 5:4; 15:30). This accords with the Old Testament dispensation of legal retribution (Ex 20:5).

Matthew Henry's Concise Commentary

17:1-9 Job reflects upon the harsh censures his friends had passed upon him, and, looking on himself as a dying man, he appeals to God. Our time is ending. It concerns us carefully to redeem the days of time, and to spend them in getting ready for eternity. We see the good use the righteous should make of Job's afflictions from God, from enemies, and from friends. Instead of being discouraged in the service of God, by the hard usage this faithful servant of God met with, they should be made bold to proceed and persevere therein. Those who keep their eye upon heaven as their end, will keep their feet in the paths of religion as their way, whatever difficulties and discouragements they may meet with.