Why do they dwell in graves?
Rashi: It is so Ru'ach ha'Tum'ah of demons will dwell on them.
Radak: They seek [to communicate with] the dead.
Radak citing Targum Yonasan: They dwell in houses made of earth from graves.
What are "Netzurim"?
Rashi: They are dead bodies. It is as if they are in a Matzur (siege), and cannot leave.
Radak: They are ruins. They lodge in them at night, for they think that demons will appear to them. Mazikin (damaging spirits) appear in ruins to those who believe in them. Similarly, "u'Netzurei Yisrael Lehashiv" (49:6) refers to ruins.
Radak citing Targum Yonasan: Dead human bodies.
Malbim: They are places where they cast animal carcasses. They hide there lest people see them when they eat pork.
Why do they eat pork?
Radak: They transgress everything that the Torah forbade.
What is "u'Merak Pigulim"?
Rashi: It is gravy that became thick. This is like "v'Es ha'Marak Shefoch" (Shoftim 6:20).
Radak: This includes all other Tamei animals and vermin. All of them are Pigulim and despised.
Why does it mention their Kelim?
Radak: From the lard stuck to them, one recognizes that pork and vermin were cooked in them. If they want to deny eating them (the lie will be evident).
Malbim: Their Kelim absorbed the gravy of the abominations that they ate.
