About
The firstborn child of the Prophet ﷺ and Khadīja, born in Makkah before the revelation. From him the Prophet ﷺ took his kunya, Abū al-Qāsim, 'father of al-Qāsim', the name by which he was addressed throughout his life and which he told others not to take for themselves, explaining that Allah gives and he only distributes (Bukhārī). Al-Qāsim died in early childhood; none of the Prophet's ﷺ sons lived beyond early childhood.
The name
'The one who divides and distributes', from qasama; the Prophet ﷺ took his kunya Abū al-Qāsim from him.
Source: Ṣaḥīḥ hadith
Relationships
FatherHis father, who took his kunya from him
MotherHis mother; he was her firstborn