The difference between dust and trash is that dust is something natural that was made this way while trash is waste. Our sages said, “None are poorer than a dog and none richer than a swine” (Shabbat 155b), since a swine finds its nourishment everywhere, for waste, too, is food for a swine.
We should interpret that as long as one has not corrected the sin of the primordial serpent, all of one’s flavor in Torah and Mitzvot [commandments] is only as dust. This is called “Shechina [Divinity] in the dust.” One’s aim in Torah and Mitzvot should be that through our work we can raise the Shechina from the dust.
This extends from the creation of the worlds, which was with the intention that we would be able to make the correction of equivalence of form, as our sages said, “As He is merciful, so you are merciful” (Sotah 14a). Hence, Tzimtzum [restriction] and concealment were placed on the vessels of reception so as to be a vacant space devoid of Kedusha [holiness]. This is why by creation, there is the taste of dust.
This is why the verse says “He Raises the Poor from the Dust,” meaning that the Shechina is called poor and meager because everyone sees that she has nothing to give in return for engaging in Torah and Mitzvot.
It follows that all of people’s pleasures are only from waste of Kedusha that extends into the corporeal pleasures. It is called “tiny light,” and it sustains the Klipot [shells/peels], and this is called “trash.”
Hence, He raises from the trash, meaning He has to lift man so he will not be taken after the ignoble pleasures called “trash.” When he refrains from trash, he is rewarded with raising the Shechina from the dust, since one depends on the other.