'Unfaithfully' in the Bible

But the sons of Israel acted unfaithfully in regard to the things under the ban, for Achan, the son of Carmi, the son of Zabdi, the son of Zerah, from the tribe of Judah, took some of the things under the ban, therefore the anger of the Lord burned against the sons of Israel.

Did not Achan the son of Zerah act unfaithfully in the things under the ban, and wrath fall on all the congregation of Israel? And that man did not perish alone in his iniquity.’”