Question: A non-Muslim friend asks about the meaning of the terms Sal, Alai, Rali, and Rah that Muslims append to the names of past figures. How should I explain this?
– Tasleem, Chennai.
Answer: Sal is an abbreviation for Sallallahu Alaihi Wasallam.
Although written as Sal, it should be read as Sallallahu Alaihi Wasallam. Its meaning is: "May Allah bestow special blessings and peace upon him." When Prophet Muhammad (PBUH) is mentioned, one must pray for divine blessings upon him; the Prophet himself emphasized this. Therefore, when mentioning Prophet Muhammad, we include the phrase, "May Allah bestow blessings upon him."
While other communities have turned the prophets sent to guide them into deities, this honorific prevents Muslims from elevating Prophet Muhammad (PBUH) to the status of a god.
It instills a clear understanding within the Muslim community that whenever we speak of Prophet Muhammad, we pray for him, not to him.
Alai is an abbreviation for Alaihis-Salam or Alaihis-Salatu-was-Salam.
It is customary to use this term when referring to prophets other than Prophet Muhammad (PBUH). Its meaning is: "May divine blessings and peace be upon him." In other words, Alaihis-Salatu-was-Salam carries the same meaning as Sallallahu Alaihi Wasallam.
There is nothing wrong with using terms like "Prophet Muhammad (Alai)" or "Musa (Sal)." Many have used these terms in this manner in ancient texts as well.
However, it has become customary to use "Sal" (short for Sallallahu Alaihi Wasallam) specifically for Prophet Muhammad (PBUH) and "Alai" (short for Alaihis Salam) for other prophets.
There is no religious objection to using "Alai" for individuals other than prophets; it simply means "may peace and mercy be upon them." It is a suppication (dua) that can be made for anyone.
"Rali" is an abbreviation of "Radiyallahu Anhu," meaning "may Allah be pleased with him."
This term can be applied to any believer, as everyone seeks Allah's pleasure.
Nevertheless, its usage has become associated exclusively with the Companions of the Prophet. Yet, using "Rali" for those who are not Companions is not a violation of religious law.
One could even refer to you as "Tasneem (Rali)." However, the term "Rali" has transcended its literal meaning to become a specific identifier for the Prophet's Companions. Using it for others might create the impression that they were among the Prophet's Companions.
Bearing this in mind, it is best to avoid using it for others.
"Rah" is an abbreviation of "Rahmatullahi Alaihi," meaning "may Allah have mercy upon him."
This term can be used for all believers, as everyone is in need of Allah's mercy. However, in practice, it is used only for the deceased—and specifically for prominent figures. If it were used for you or me, people might assume we lived and passed away long ago. Still, it can be used for anyone; there is no religious prohibition against it.