"Living and dead?" Meaning: they are on its surface alive, and they are in its belly dead. Muhammad said: You say, "kaftu al-shayʾa akfituhu" and you say, "akfit ilayka kadhā," meaning: gather it, and they used to call the graveyard a "kafta" because it gathers the dead.
﴿أَحيَاء وأمواتا﴾ أَيْ: يَكُونُونَ عَلَى ظَهْرِهَا أَحْيَاءً، وَيَكُونُونَ فِي بَطْنِهَا أَمْوَاتًا.
قَالَ مُحَمَّدٌ: تَقُولُ: كَفَتُّ الشَّيْءَ أَكْفِتُه وَتَقُولُ: أَكْفِتْ إِلَيْكَ كَذَا، أَيْ: ضُمَّه، وَكَانُوا يُسَمُّونَ الْمَقْبُرَةَ كَفْتَةً؛ لِأَنَّهَا تضمُّ الْمَوْتَى.