The Qur’an’s grammar matters absolutely and conveys vital meaning. Tense, person, case, all matter for the message. What is obvious to the wise is subtle to the dummy. If something is worded in the dual and not the plural then it is that way for a reason. If there is a dialog ...
So here one has to turn to Quran to see if there is any help to this meaning of ‘a day’, surely Allah says in Quran: 22:47 Yet they ask thee to hasten on the Punishment! But Allah will not fail in His Promise. Verily a Day in the sight of thy Lord is like a thousand year...