Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
LXX2012

Prayer of Manasseh 1:6

the mercy of your promise is both immeasurable and inscrutable;

Parallel Translations

LXXView canonical →
the mercy of thy promise is both immeasurable and inscrutable;
Brenton's Septuagint Translation