'Dust' in the Bible

My dear people, dress yourselves in sackclothand roll in the dust.Mourn as you would for an only son,a bitter lament,for suddenly the destroyer will come on us.

Wail, you shepherds, and cry out.Roll in the dust, you leaders of the flock.Because the days of your slaughter have come,you will fall and become shattered like a precious vase.