# in the day of Yahweh's rage

"in the day when Yahweh acts on his anger" or "when Yahweh punishes them"

# the day

This can be a time period of more or less than one 24-hour day.

# their hunger will not be satisfied

"they will not be able to satisfy their hunger"

# their iniquity has become a stumbling block

"because they are evil, they are committing sins that show how evil they are."