Afar means dust, loose earth, dry soil, or the fine powder of crushed material. It occurs about 110 times in the OT. It represents both the material substance of the ground and, theologically, the humility and mortality of the human condition.
The word is connected to the creation account — man was formed from the afar of the ground (Genesis 2:7) and will return to it (Genesis 3:19). Dust is not an insult but a creaturely designation: we are earth-creatures animated by the divine breath.
The phrase "dust to dust" defines the arc of mortal life. Job, in his suffering, says he knows his Redeemer lives even though worms destroy his body (Job 19:25–26) — the hope of resurrection must overcome the reality of afar.
Sitting in afar (dust and ashes) was a posture of grief, mourning, and radical humility before God (Job 2:12; 42:6). To be brought "to the dust of death" (Psalm 22:15) is to reach the end of human strength — which is precisely where God acts.
Afar appears in the key promise to Abraham: his offspring will be as countless as the afar of the earth (Genesis 13:16; 28:14). Dust — the symbol of mortality — becomes the symbol of innumerable blessing. God specializes in reversing what dust represents.