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

Baruch 2:29

If ye will not hear my voice, surely this very great multitude shall be turned into a small [number] among the nations, where I will scatter them.

Parallel Translations

LXX2012View canonical →
If you⌃ will not hear my voice, surely this very great multitude shall be turned into a small number among the nations, where I will scatter them.
Septuagint in American English (2012)
KJVView canonical →
If ye will not hear my voice, surely this very great multitude shall be turned into a small number among the nations, where I will scatter them.
King James Version
WEBView canonical →
“If you won’t hear my voice, surely this very great multitude will be turned into a small number among the nations where I will scatter them.
World English Bible