Tafseer Ibn Kathir of FUSHSHILAT [54]

أَلَا إِنَّهُمْ فِي مِرْيَةٍ مِّن لِّقَاء رَبِّهِمْ أَلَا إِنَّهُ بِكُلِّ شَيْءٍ مُّحِيطٌ

Unquestionably, they are in doubt about the meeting with their Lord. Unquestionably He is, of all things, encompassing.