"And in anything over which you differ, its decision is with Allah," meaning: whatever you differed about regarding disbelief and faith. "Its decision is with Allah," so He will admit the believers into Paradise and admit the polytheists into the Fire. "Such is Allah, my Lord," He says to the Prophet (peace be upon him): Tell them, "Such is Allah, my Lord."
Muhammad said: Ibn Mujahid mentioned that the ya' is established in 'rabbi' (my Lord) because it is a possessive pronoun. He said:
﴿وَمَا اخْتَلَفْتُمْ فِيهِ مِن شَيْءٍ﴾ يَعْنِي: مَا اختلفتم فِيهِ من الْكفْر وَالْإِيمَان ﴿فَحُكْمُهُ إِلَى اللَّهِ﴾ فَيُدْخِلُ الْمُؤْمِنِينَ الْجَنَّةَ، وَيُدْخِلُ الْمُشْرِكِينَ النَّار ﴿ذَلِكُمُ اللَّهُ رَبِّي﴾ يَقُولُوا للنَّبِي ﷺ قل لَهُم: ذَلِكُم الله رَبِّي.
قَالَ محمدٌ: ذكر ابْنُ مُجَاهِد أَن الْيَاء ثَابِتَة فِي ﴿رَبِّي﴾ لِأَنَّهَا إِضَافَة قَالَ:
