Can you tell me why the word Ummah is in the accusative (Mansūb) rather than being in the genitive (Majrūr) in verses 3:150 and 20:94 of the Qur’ān?
It is very common in Arabic that when the word Ibn is used in the vocative case (Munādā), particularly when used at the time of expressing affection and love, the appended noun (Mudaf-ilayh) can be declined in the nominative case (Marfu‘), accusative (Mansūb) as well as the genitive (Majrūr) case. All the three forms are used by the Arabs at such instances, as is specified by the celebrated grammarian Zamakhsharī in his treatise on Arabic Grammar (section on Munādā).1
_________________ 1. Zamakhsharī, Mufassal, [Lahore: Dāru’l-Nashr al-Kutub al-Islāmiyyah] p. 43