﴿ مَا يَأْتِيهِم مِّن ذِكْرٍۢ مِّن رَّبِّهِم مُّحْدَثٍ إِلَّا ٱسْتَمَعُوهُ وَهُمْ يَلْعَبُونَ ﴾

“Whenever there comes unto them any new re­minder from their Sustainer, they but listen to it with playful amusement,”

(Never cometh there unto them) whenever Gabriel comes to their Prophet with (a new reminder from their Lord) i.e. the Qur'an: verse after verse and surah after surah, as if the coming of Gabriel, time after time, and the recitation of Muhammad (pbuh) and their listening to it are new, not that the Qur'an is new, (but they listen to it while they play) while they mock Muhammad (pbuh) and the Qur'an.