Radak: See what is written on the tablet; afterwards, write it in a Sefer so it will be testimony for much later.

Malbim: It is a small tablet that will remain with them for a remembrance for them themselves, until "Yom Acharon" - the end of their lives.

Rashi: Carve [this Nevu'ah]. Malbim - carve it with an iron stylus, so it will last for future generations.

Radak: They and those who come after them will see that I did not bring punishments for naught, rather, for their sin. They are a rebellious nation. I already testified against them day after day through my Nevi'im, and they did not want to listen.