Thou writest, i.e. thou appointest or inflictest. A metaphor from princes or judges, who anciently used to write their sentence or decrees concerning persons or causes brought before them. See Psalms 149:9 Jeremiah 22:30 1 Thessalonians 19:22. Bitter things, i.e. a terrible sentence, or most grievous punishments. Makest me to possess the iniquities of my youth; thou dost now at once bring upon me the punishment of all my sins, not excepting those of my youth, which because of the folly and weakness of that age are usually excused or winked at, or at least but gently punished.
Related Commentaries of Job 13:26
Job 13:26
26 For thou writest bitter things against me, and makest me to possess the iniquities of my youth.