Using “’Alayhi As-Salaam” for other than the Prophets
28-8-2011 | IslamWeb
Question:
Assalam u alaikum. My question is regarding Hazrat Ali (RzA). Many Sunni people use "Alaihi salaam" to Hazrat Ali ,Hazrat hussain etc.So is it permissible?How can we refute them... They put their argument as "Alaihi salaam" is used for hazrat maryam , although also she was not a prophet.similarly for Hazrat Khizr and Imaam Mehdi. plz provide me with refernences so that i can make him understand. Jazakkallah
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
Using the expression “‘Alayhi As-Salaam” (which means invoking blessings on someone) for ‘Ali or other Companions 
or for other than the Companions, is permissible because its meaning is correct. Similarly, saying ‘
’, when mentioning a Taabi’i (someone from the generation that followed the generation of the Companions) is permissible, because all this is like supplicating for them.
However, in general we say “‘Alayhi As-Salaam” when mentioning a Prophet, and we say ‘’ when mentioning one of the Companions, and we say ‘
’ when mentioning one of the Taabi’ieen (plural of Taabi’i) and those who came after them, and so forth.
So, contradicting this general principle when mentioning one of the Companions or Taabi’ieen in particular, such as saying “‘Alayhi As-Salaam” when mentioning his name as some people do when mentioning ‘Ali or Faatimah, or Al-Hasan or Al-Husain, and not when mentioning others, then this should not be done. Ibn Katheer said in his Tafseer: “I said: “It has become ordinary that many scribes of books single out ‘Ali by specifically saying “‘Alayhi As-Salaam” or saying “Karrama Allaahu Wajhah (i.e. may Allaah honor his face)” when mentioning his name and not when mentioning the names of all other Companions. Even though the meaning is correct, yet one should put all the Companions on an equal footing in this regard, because if this is said about him [‘Ali] as a way of honoring him and glorifying him, then Abu Bakr, ‘Umar and ‘Uthmaan come in priority over him, may Allaah be pleased with all of them.”
In addition to this, it should be mentioned that there is a difference of opinion among the scholars about the ruling on using “‘Alayhi As-Salaam” for other than the Prophets.
Allaah Knows best.