"There does not come to them a new reminder from their Lord" means: the Quran, "except that they listen to it while they are playing," meaning they hear it with their ears, but their hearts do not accept it.
﴿مَا يَأْتِيهِمْ مِنْ ذِكْرٍ مِنْ رَبهم مُحدث﴾ يَعْنِي: الْقُرْآنَ ﴿إِلا اسْتَمَعُوهُ وَهُمْ يَلْعَبُونَ﴾ يَسْمَعُونَهُ بِآذَانِهِمْ، وَلَا تَقْبَلُهُ قُلُوبُهُمْ