1) I’ve recently read some authentic ahadith as well as views of classical scholars such as al-Kulayni, Allama Majlisi that state Rasullulah (SAW) had 4 daughters and not 1. What are the views of the modern scholars and maraja3 on this? If he did have 4 daughters, how do we reconcile with them being married to Kuffar?

2) Why does Allah (swt) use the plural word of daughters in the verse instructing the Prophet (saw)? I understand the same was used in the verse of Mubahila but here daughters is specific rather than women?

1) This is a matter of disagreement

Ayatollah Jafar Amili who has written one of the biggest biographies of the Prophet (over 40 volumes) concluded that the prophet had one daughter only. I agree with this and evidence points to this, such as praise of sayida and no praise of other 3 for eg

2) It’s because of his adopted daughters. They were daughters of the sister of Khadija Hala.