[Machine] When the Messenger of Allah ﷺ recited "In the name of Allah, the Most Gracious, the Most Merciful," the polytheists would mock him and say, "Muhammad mentions the deity of the Yamama tribe." And Musaylimah would call himself "Ar-Rahman" (the Most Merciful). So when the verse "The Messenger of Allah is not supposed to make it known" was revealed...
كَانَ رَسُولُ اللهِ ﷺ إِذَا قَرَأَ بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ هَزِئَ مِنْهُ الْمُشْرِكُونَ وَقَالُوا مُحَمَّدٌ يَذْكُرُ إِلَهَ الْيَمَامَةِ وَكَانَ مُسَيْلِمَةُ يَتَسَمَّى الرَّحْمَنَ فَلَمَّا نَزَلَتْ هَذِهِ الْآيَةُ «أُمِرَ رَسُولُ اللهِ ﷺ أَنْ لَا يَجْهَرَ بِهَا»