It's a truncated quote from Diderot. The full verse is:

J’en atteste les temps ; j’en appelle à tout âge ;
Jamais au public avantage
L’homme n’a franchement sacrifié ses droits ;
S’il osait de son cœur n’écouter que la voix,
Changeant tout à coup de langage,
Il nous dirait, comme l’hôte des bois :
« La nature n’a fait ni serviteur ni maître;
« Je ne veux ni donner ni recevoir de lois. »
Et ses mains ourdiraient les entrailles du prêtre,
Au défaut d'un cordon pour étrangler les rois.

A slightly better translation would be:

I bear witness to the times; I appeal to all ages;
Never, for the public good,
Has man willingly sacrificed his rights;
If he dared to listen only to the voice of his heart,
Suddenly changing his tone,
He would say to us, like the dweller of the woods:
“Nature has created neither servant nor master;
“I wish neither to give nor to receive laws.” 
And his hands would tear out the priest’s entrails,
For lack of a cord to strangle kings.

It is the voice of the forest, dweller of the woods being a stand in for anarchists. So the hands strangling kings with priest's entrails are those of the man realizing the importance of rights and freedom. Diderot elaborates across the poem about the character of political order. Declaring that no law or political rule is sacred or natural. Mankind makes sociopolitical structures, they are not natural, and thus nature will gladly unmake them, as a king dying, for example. Essentially, he says that no elevated, supernatural, or godly power exists that will stop the hands of a person who has chosen to defy political oppression. It was extremely controversial in the XVIII century, a liberal cry for revolution against political systems that still stood over the pillars of a god given right of monarchs to rule. It's called Les éleuthéromanes, I'm not gonna try to translate that, but the full text can be found freely.

Worse yet it's missing some good context that dustyData shared in this thread. I just included it in reference to the quote I thought of