In this article I argue that Augustine's four late works against the so-called “Semi-Pelagians” can be read creatively and reparatively alongside the book of Job. Specifically, Augustine's frequent appeals to the inscrutability of God's judgment can be compared with God's speeches to Job out of the whirlwind. Having shown how the latter operate “indexically”, I will return to Augustine to highlight signs of indexicality throughout his four works. This will allow an interpretation of Augustine's doctrine of predestination, and its culminating moments of inscrutability, not as timeless truth, but as a tool used within prayer and preaching to foster salvation.