Devarim 24:16 makes a statement which is central to Jewish theology. The posuk makes clear that a father will not be put to death for the sins of his son and that a son will not be put to death for the sins of his father – the gemara develops this to say that neither shall be put to death through the testimony of the other. Then, to expand on the first part, lest one think that people outside of the family can receive punishment on behalf of others, the verse concludes “ish b’chet’o yumatu” a man, in his own sin, will be put to death. This idea of banning vicarious expiation of sin through the death of another forms a solid challenge to any religious system predicated on the death of another to atone for the sins of a person who remains, effectively, unpunished.
לֹא-יוּמְתוּ אָבוֹת עַל-בָּנִים, וּבָנִים לֹא-יוּמְתוּ עַל-אָבוֹת: אִישׁ בְּחֶטְאוֹ, יוּמָתוּ.
However, there is a grammatical problem with the posuk – it states in those final three words “ish (a man) b’chet’o (in his sin) yumatu (they will be put to death, or possibly he will be put to death by them)” – the final vav turns the word “yumat” into some form of a plural. This plural form appears only three other times in tanach. In those, the actions of two parties condemned them both to the death penalty (vayikra 20:13, 16, 27). Here, the verse clearly limits the offender and offense to the singular as an explicit shift from the first part of the posuk with reads “lo yumtu avot” that father*s* shall not be put to death (Onkelos translates both "yumtu" and "yumatu" as "y'mootoon" and T"Yonatan has both being "yitkatlun"). The singular verb (yumat) occurs almost 50 times, both in conjunction with “mot” (as in “mot yumat”) and on its own. Why would this verse switch to a pluralized action and to what does the plural refer? What doesn’t the posuk simply read “ish b’chet’o yumat”?