Epher (אֵפֶר) refers to ashes — the residue left after burning. Ashes held profound symbolic significance in ancient Israel: they were worn as a sign of mourning, grief, and repentance. Sitting in ashes or covering oneself with ashes communicated utter humility before God or in the face of catastrophic loss.
The movement from ashes to glory is one of Scripture's great redemptive arcs. Isaiah 61:3 promises God will give "a garland instead of ashes" to those who mourn in Zion — a direct messianic promise fulfilled in Jesus Christ. Ashes speak of our mortality and frailty; the exchange God offers is beauty, joy, and praise in their place.