Tafsir of Al-Qasas 28:52

{ Those to whom We gave the Book before it }—meaning before the Quran—on the premise that the pronoun refers to the "Word" (meaning the Quran) or to the Quran understood from it. In either case, the intent is: before it was given to them. { they }—not those whose conditions were previously mentioned—{ believe in it }—that is, in the Quran.

It is said that both pronouns refer to the Prophet, peace be upon him. The intent of the relative pronoun, according to what is narrated from Ibn Abbas, is the believers among the People of the Book generally.

It is also said that they are Abu Rafa‘a and ten other Jews who believed and were persecuted. Ibn Mardawayh recorded a report with a good chain of narration, along with a group, from Rifa‘a al-Qurazi that supports this.

It is also said that they are forty people from the followers of the Gospel who were believers in the Messenger, may Allah exalt him and grant him peace, before his mission: thirty-two from Abyssinia who arrived with Ja‘far ibn Abi Talib, and eight who came from the Levant: Bahira, Abraha, Ashraf, ‘Amir, Ayman, Idris, Nafi‘, and Tamim.

It is further said that they are Ibn Salam, Tamim al-Dari, al-Jarud al-‘Abdi, and Salman al-Farisi. This is attributed to Qatadah. Abu Hayyan favored the general interpretation, suggesting that what was mentioned serves as an example of those among the People of the Book who believed.