John Gill Commentary Jeremiah 36:31

"And I will punish him and his seed and his servants for their iniquity; and I will bring upon them, and upon the inhabitants of Jerusalem, and upon the men of Judah, all the evil that I have pronounced against them, but they hearkened not." — Jeremiah 36:31 (ASV)

And I will punish him and his seed and his servants for their
iniquity
In cutting the roll pieces, and burning it, as Abarbinel interprets it; which either was done by himself, or by his order, and with his connivance; and at which perhaps his sons were present, and expressed a pleasure in it; and his servants that stood by assented to it, excepting three; nor were they afraid of the judgments of God for it, nor in the least shocked at it, (Jeremiah 36:24Jeremiah 36:25) ; though this may be understood of all their iniquities they had been guilty of, the singular being put for the plural: and I will bring upon them, and upon the inhabitants of Jerusalem, and
upon the men of Judah, all the evil that I have pronounced against
them ;
the sword, famine, and pestilence; the destruction of their land, city, and temple; and their captivity in Babylon: but they hearkened not ;
to what was said to them, neither in the first nor in the second roll.