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

Numbers 10:6

And ye shall sound a second alarm, and the camps pitched southward shall move; and ye shall sound a third alarm, and the camps pitched westward shall move forward; and ye shall sound a fourth alarm, and they that encamp toward the north shall move forward: they shall sound an alarm at their departure.

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