Muhammad said: Regarding the one who recites: "Your Lord has decreed upon Himself mercy that (annahu)," with the fathah on the alif, the meaning is: "And He has decreed that (annahu)." As for the one who recites: "Then indeed (fa-innahu), He is Forgiving, Merciful," with the kasrah on the alif, it is in the state of being a new sentence (isti'naf).
قَالَ مُحَمَّدٌ: وَمَنْ قَرَأَ: ﴿كَتَبَ رَبُّكُمْ عَلَى نَفْسِهِ الرَّحْمَةَ أَنَّهُ﴾ بِفَتْحِ الْأَلِفِ، فَالْمَعْنَى: وَكَتَبَ أَنَّهُ، وَمَنْ قَرَأَ: ﴿فَأَنَّهُ غَفُورٌ رَحِيمٌ﴾ بِكَسْرِ الْأَلِفِ؛ فَإِنَّهُ عَلَى الِاسْتِئْنَافِ.