Surah 83. Al-Mutaffifin, Ayah 9

 This is based on the commentary of Ibn Kathîr.

If we take Sijjin to be the Register itself, and not the place where it is kept, the Register itself is a sort of Prison for those who do wrong. It is inscribed fully: i.e., no one is omitted who ought to be there, and for every entry there is a complete record, so that there is no escape for the sinner.