en_tn/isa/44/20.md

It is as if he were eating ashes

Yahweh speaks of a person worshiping an idol as if that person were eating the burned ashes of the wood from which he made the idol. Just as eating ashes does not benefit a person, neither does worshiping an idol. (See: rc://en/ta/man/jit/figs-metaphor)

his deceived heart misleads him

The heart represents the inner person. Alternate translation: "he misleads himself because he is deceived" (See: rc://en/ta/man/jit/figs-metonymy)

He cannot rescue himself

"The person who worships idols cannot save himself"