'Ashes' in the Bible

O daughter of my people, gird thee with sackcloth, and wallow thyself in ashes: make thee mourning, as for an only son, most bitter lamentation; for the destroyer shall suddenly come upon us.

Wail, ye shepherds, and cry; and wallow in ashes , ye principal of the flock; for the days of your slaughter and of your dispersions are fully come, and ye shall fall like a goodly vessel.

And the whole valley of the dead bodies and of the ashes, and all the fields unto the brook Kidron, unto the corner of the horse gate toward the east, shall be holy unto Jehovah; it shall not be plucked up, nor thrown down any more for ever.