C. F. Keil and Franz Delitzsch on Deuteronomy 29:20-21

Deu 29:20-21 “For the Lord will not forgive him (who thinks or speaks in this way); but then will His anger smoke (break forth in fire; vid., (Psa 74:1), and His jealousy against that man, and the whole curse of the law will lie upon him, that his name may be blotted out under heaven (vid., Deu 25:19; Exo 17:14). “The Lord will separate him unto evil from all the tribes, - so that he will be shut out from the covenant nation, and from its salvation, and be exposed to destruction - according to all the curses of the covenant.” Although the pronominal suffix refers primarily to the man, it also applies, according to Deu 29:18, to the woman, the family, and the tribe. “That is written,” etc., as in Deu 28:58, Deu 28:61.