"For them is a bed of Hell," meaning: a mattress. "And from above them are coverings [of fire]," meaning: what covers them from the Fire.
﴿لَهُم من جَهَنَّم مهاد﴾ أَيْ: فِرَاشٌ ﴿وَمِنْ فَوْقِهِمْ غَوَاشٍ﴾ يَعْنِي: مَا يَغْشَاهُمْ مِنَ النَّارِ.
