The word "Ragham" means soil. When a person's nose is soiled, it is a mark of his extreme humiliation. This metaphor carries a curse for an unfortunate person who does not win the pleasure of Allah by serving and obeying his parents. In fact, it is a malediction as well as a prediction of someone's inauspicious end. Service of parents is essential at every stage of their life - whether they are young or old. But this Hadith mentions their old age for the reason that in that period of their life they stand in greater need of care and service. It is a very callous offense to leave them at the mercy of circumstances when they are old, senile and depend on others for their needs. To neglect them at that stage is a major sin for which one deserves Hell-fire.