Isaiah 65 piles up charges of idolatry and impurity against Israel. They are supposed to offer continuous sacrifices, but their sacrifices are a continuous provocation (65:3). They build their altars from bricks rather than from stones, as the law requires (65:3). The sacrificial smoke doesn’t sooth Yahweh but is an irritation to His nostrils (65:5). 

Besides, they are in a continuous state of uncleanness. They inhabit graveyards, and eat pig flesh that’s cooked in impure broth (65:4). Contact with death produced an especially intense form of impurity (Numbers 19), and “inhabiting” cemeteries was unthinkable. Verse 4 seems to be describing assemblies at the graves of the dead - perhaps a hero cult that involved nighttime worship at the tomb of the hero.

What seals Isaiah’s condemnation, though, is the beginning of verse 5: Though drenched in impurity, the people claim to be particularly holy, too holy for any to draw near (v. 5). Though living in graveyards and eating unclean flesh, they claim to be worried that someone will come too close, touch them, and so defile them. Their state of defilement has become a point of pride.

It’s an incisive portrait of “Pharisaism,” which is not simply pride, not simply pride in holiness, but the holiness-pride of the impure. It’s the blindness of the rebellious who believe they are models of submission. And it’s not confined to the 8th century BC or the 1st AD.