وَمَا أَنزَلْنَا عَلَيْكَ الْكِتَابَ إِلَّا لِتُبَيِّنَ لَهُمُ الَّذِي اخْتَلَفُوا فِيهِ وَهُدًى وَرَحْمَةً لِّقَوْمٍ يُؤْمِنُونَ
We did not send down the Book to you except [for the purpose] that you may clarify for them what they differ about, and as a guidance and mercy for a people who have faith.
Agha Ali Puya Commentary
Commentary on Quran 16:64
[Pooya/Ali Commentary 16:64] "Which they differ", may cover polytheism, dualism, trinity, crucification and resurrection of prophet Isa, and what is permissible and what is forbidden, and in fact all other points of difference .