Ô que ta main par là va sauver de pupilles!
Que de sçavans plaideurs desormais inutiles!

Que d’ illustres témoins de ta vaste bonté
Vont pour toy déposer à la posterité!

(translated from French)

By them, your hand will save the helpless
Men of law and their learned debates now have no meaning

Great men will be witness to your extraordinary goodness;
they will set you down in posterity.

From Epîtres [letters] by Par Nicolas Boileau-Despreaux (1636-1711).

Thanks to Matthew Quirk (at Atlantic Monthly) and Miranda Mouillot (a translator in Paris) for helping with the translation
and adding some insight to it. Miranda says:

“I’m not at all sure that this is supposed to be a joke.

The poem is talking about the king’s laws, (poet worked for the king)
and the Code Civil was and is still respected in France in much the
same way that the king’s laws are in the poem—remember that French
people for the most part liked Napoleon’s domestic policy. It’s
important to remember that for most French people, their history is
(crazy to think) continuous, and your average inscription writer is
probably going to be thinking of the Code Civil as consistent with an
overarching French idea of wise legislation, rather than making a flip
political comment. That’s what I’d guess, at least.”