In Chapter 10, Poem 22 of the Mokhtar Nameh, Attar uses the metaphor of rust to describe the corrupting influence of worldly attachment on the human soul. Just as rust prevents a metal surface from reflecting light, worldly grief and desires obscure the soul, rendering it incapable of receiving spiritual illumination. Consequently, a life consumed by material worries deprives the individual of experiencing the spiritual delights of the hereafter.