What is the reason for "al-birr" (piety/righteousness) being in the nominative case (al-birru) in the noble verse: "And al-birru (it is) not that you come to houses from their doors..."? And what is the reason for it being in the accusative case (al-birra) in the noble verse: "Al-birra (it is) not that you turn your faces towards the East and the West..."?

In the verse: "And there is no righteousness in your entering houses from their backs," the word "al-birr" (righteousness) is in the nominative case because it is the name of "laysa" (is not), and its predicate is the phrase "in your entering houses." As for the verse: "Righteousness is not that you turn your faces toward the East or the West," the majority of reciters read "laysa al-birru" with "al-birr" in the nominative case. However, Hamza and Hafs from Asim recited it with "al-birra" in the accusative case, considering it the predicate of "laysa," and its name to be the phrase "that you turn." This fronting and deferring is common in Arabic. Ibn Ashour mentioned that the nominative case of "al-birr" is due to it being a well-known and familiar concept, whereas its accusative case is because the matter of facing the Qibla was the primary concern of the recipient.