Ibn Abbas commented on the verses "And for everyone We have appointed heirs" and "and those with whom your right hands have made a pledge" [Nisa 4:33].He explained that when the Emigrants first arrived in Madinah, an Ansari would inherit from an Emigrant to the exclusion of the Emigrant's own blood relatives, because of the bond of brotherhood the Prophet ﷺ had established between them. Then, when "And for everyone We have appointed heirs" [Nisa 4:33] was revealed, Ibn Abbas said it abrogated "and those with whom your right hands have made a pledge" [Nisa 4:33].
حدثني إسحاق بن إبراهيم قال قلت لأبي أسامة حدثكم إدريس حدثنا طلحة
عن ابن عباس {ولكل جعلنا موالي} {والذين عاقدت أيمانكم} قال كان المهاجرون حين قدموا المدينة يرث الأنصاري المهاجري دون ذوي رحمه للأخوة التي آخى النبي ﷺ بينهم فلما نزلت {ولكل جعلنا موالي} قال نسختها {والذين عاقدت أيمانكم}