Rahimahullah is an Arabic honorific meaning "May Allah have mercy on him." It is traditionally used when mentioning the name of a deceased Muslim who was known for their piety, scholarship, or service to the faith (but who was not a companion of the Prophet). For example, it is used for great Imams like Abu Hanifa or Al-Bukhari. This phrase is an act of "Du'a" for the deceased, reflecting the Islamic belief in the continuity of the relationship between the living and the dead through prayer and the ongoing need for divine mercy in the afterlife. The phrase is derived from "Rahmah" (mercy), one of Allah's primary attributes. Asking for mercy for the deceased is a form of charity that benefits them after death. The Prophet taught that when a person dies, their deeds cease except for three: ongoing charity, beneficial knowledge, and a righteous child who prays for them. Saying Rahimahullah for scholars and righteous individuals is a way of continuing to benefit them through supplication. The honorific is used for both male and female deceased, with "Rahimahallah" for males and "Rahimahallah" (or sometimes "Rahimaha Allah") for females. It is used for scholars, leaders, family members, and any Muslim who has passed away. For companions of the Prophet, the honorific "Radiyallahu Anhu" is used instead, as their status is established by Allah's pleasure with them. For scholars and righteous Muslims, Rahimahullah is the appropriate supplication, acknowledging that their fate is in Allah's hands and asking for mercy. Using this phrase is also a reminder of death and the Hereafter. Mentioning the deceased with a prayer for mercy keeps their memory alive in a beneficial way and reminds the living of their own eventual return to Allah. It also fosters humility, recognizing that no matter one's status in life, all are in need of Allah's mercy after death. In scholarly circles, mentioning the great Imams of the past with Rahimahullah is a sign of respect and gratitude for their contributions to Islamic knowledge. It acknowledges that while they are gone, their legacy continues, and they are deserving of prayers for mercy.