'rejectors') refers to those Shia Muslims who 'reject' the 'legitimacy' of the caliphates of Abu Bakr (r. 632–634), Umar (r. 634–644), and Uthman (r. 644–656), in favor of Ali ibn Abi Talib (r. 656–661), the cousin and son-in-law of the Islamic prophet Muhammad.
In particular, the term Rafida appears in Sunni polemics as a derogatory nickname for Twelvers, who constitute the overwhelming majority of the Shia community.
[5] Twelvers believe that, shortly before he died, Muhammad publicly designated his cousin and son-in-law, Ali ibn Abi Talib, as his successor at the Ghadir Khumm.
[8] They are labeled today as infidels or heretics by various Salafi and Wahhabi scholars,[9][10] considered a bigger threat to Islam than Christianity and Judaism,[8][10] and there are frequent calls for their extermination.
[13][14] A popular reference for these groups is the prominent Hanbali theologian Ibn Taymiyya (d. 1328), a staunch anti-Shia who also accused the Shia of conspiring with nonbelievers to destroy Islam from within.
[21] In the contemporary era, some Shias in Iraq and Lebanon view the term as a source of pride, symbolizing revolt against tyranny.
[24] For Sunnis, the term signified the rejection of the first three caliphs,[24] whom Twelvers count among infidels for allegedly usurping Ali ibn Abi Talib's right to succeed Muhammad.
In one such tradition, Rafida are identified as a small group among the people of Pharaoh who rejected his rule, undaunted by his threats of punishment.
[27][28] Even though Zayd likely viewed Ali as the best amongst the companions of the Islamic prophet and the most qualified to succeed him,[29][30] he also regarded the caliphates of Abu Bakr and Umar as permissible.