Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
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Exodus 34:7

keeping loving kindness for thousands, forgiving iniquity and disobedience and sin; and who will by no means clear the guilty, visiting the iniquity of the fathers on the children, and on the children’s children, on the third and on the fourth generation.”

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