ישעיהו, פרק ס״ה, פסוק ד׳

People who wander away from the right path sometimes choose to perform dark rituals in hidden places, mixing spiritual impurity with forbidden foods. They spend their time in cemeteries with the specific goal of communicating with the dead, hoping the deceased will appear to them in their night dreams [רד״ק, שד״ל, ביאור שטיינזלץ, אבן עזרא]. Alternatively, they sit among the graves to invite a spirit of impurity from demons to rest upon them [רש״י, מצודת דוד].

These individuals also sleep in isolated, desolate locations. The primary approach among commentators is that they seek out ruined, hidden places and underground tunnels where they can hide from others or encounter demons, which are known to appear in ruins [רד״ק, שד״ל, אבן עזרא, ביאור שטיינזלץ]. Others suggest they sleep among dead bodies; since the dead cannot move from their place, they are described conceptually as being trapped or under siege [רש״י, מצודת דוד, מצודת ציון]. A third view understands these locations as filthy dumping grounds where animal carcasses are discarded and buried [מלבי״ם].

Alongside these dark practices, they blatantly violate Torah law by eating pig meat. This act is done with the direct intention of angering God [אבן עזרא], as part of a ritual for idol worship [שד״ל], or simply to consume impure foods in secret, away from the eyes of others [מלבי״ם].

Their rebellion extends to the very dishes they use, which are soaked and filled with a foul broth made from cooked impure meat, creeping animals, and idol sacrifices. The greasy residue of this abominable soup clings clearly to their pots and bowls. Even if they try to deny what they do in the dark, their own cooking vessels stand as silent witnesses, proving that they have consumed forbidden things [רד״ק].