Why God Didn't Show A Sign On Demand Of Kuffar?
Surah Anam Ayat 37
This demand was not genuine to begin with, it was asked as a way to malign the Messenger (sws) and not a serious request. Secondly , Quran has answered in another place (i.e. Quran 13:32 ) that no matter what miracles Allah will show them, they will not profess faith because of their arrogance. Lastly , Allah has finally presented Quran as a miracle and has clarified in many places that the real test is to profess faith consciously after using one’s intellect and not because of some physical miracle. For further details on this topic, please refer to the video below from 1:01 to 30:25 https://www.youtube.com/live/boFEdPJ_grY?si=1ozlBkJU6tbvbxAn&t=61