Let's add some context. Here is Isaiah 13.18-23 (LEB)
Therefore Yahweh waits to be gracious to you, and therefore he will
rise up to show you mercy, for Yahweh is a God of justice; blessed are
all those who wait for him. For people will live in Zion; in
Jerusalem, you will surely not weep. Surely he will be gracious to
you; when he hears the sound of your cry, he will answer you. And the
Lord will give you the bread of distress and the water of oppression,
but your teachers will not hide themselves any longer. And your eyes
shall see your teachers. And your ears shall hear a word from behind
you, saying, “this is the way; walk in it,” when you go to your right
and when you go to your left.
And you will defile the plating of your
silver idols and the covering of your gold image.
You will scatter
them like contaminated things;
you will say to it, “Filth!”
will give rain for your seed with which you sow the ground,
the produce of the ground,
and it will be rich and fertile.
day, your cattle will graze in broad pastures;
God is describing a process of sanctification for an idolatrous people. Paraphrasing:
- The Lord will give you bread of distress and waters of affliction
- But the teachers will speak the truth
- and (finally) you will listen and your eyes will be opened
- Then you will look at your existing idols and view them as unclean things (menstrual rags) and be disgusted by them.
- And then God will bless you with good rains, harvest, and cattle.
So the key is that dawath means contaminated or unclean and has the connotation of menstruation. Menstruation was a source of uncleanliness, which required both washing but also putting away the unclean thing. So when the people view their gold plated idols as menstrual rags, they will put them away, wash themselves, and thus repent of their idolatry.
It's a powerful image to open your eyes and see that some beautiful expensive thing that you formerly desired is a filthy thing you want to get rid of, and the source of this new revelation is the combination of affliction and honest teaching.
The hilarious (yet informative) answer about "menstrual justice" showed me the need to discuss why these bodily discharges are considered a source of uncleanliness in the case of semen/menstrual fluid and the general relationship between other discharges as feces/urine in relationship to idolatry.
First, what these discharges have in common is they are no longer of use to the body. We eat food, the food nourishes us, when all the nourishment is extracted the feces/urine contain those things that are no longer a source of nourishment. They are what's left over. We naturally find them repulsive. Same for discharges of semen or menstrual fluid, which are critical components for creating life but once discharged onto the clothes or bed, they are no longer a source of life.
Theologically, this refers to the idols that we viewed as a source of meaning and value to us, but are no longer a source of life for us. This transformation in the heart of the person who starts to view their idol as a discharge is being referenced here.
In the same way, we are not to go back to those discharges and touch them/eat them/handle them. That would be akin to backsliding or returning to Egypt. This is the theological source of what can be termed fecal/seminal/menstrual "injustice". See, for example the following references:
Mal 2.3 -- God is speaking to those who do not repent of their idolatry
"If you will not listen, and if you will not take it to heart to give
glory to my name,” says Yahweh of hosts, “then I will send the curse
on you, and I will curse your blessings; moreover I have already
cursed them because you are not taking it to heart. Look! I am going
to rebuke your offspring, and I will scatter peresh (feces) on
your faces, the peresh (feces) of your religious feasts, and you
will be carried to it. "
Ezek 4.14-15 - God makes Ezekiel eat a defiled meal in order to symbolize her backsliding
And I said, “Ah, Lord Yahweh! Look! I have not been defiling myself,
and a dead body and mangled carcass I have not eaten from my childhood
until now, and unclean meat has not come into my mouth!” And he said
to me, “See I will give you cattle manure in the place of the feces of
a human, and you may prepare your food on it.”
See also the article "keeping excrement out of God's presence"