Surah An Nahl Tafseer

أَوْ يَأْخُذَهُمْ فِي تَقَلُّبِهِمْ

Or that He may punish them in the midst of their going to and fro,

meaning, when they are busy with their daily business, travel, and other distracting activities.

Qatadah and As-Suddi said:

تَقَلُّبِهِمْ

(Their going to and fro),

means their journeys."

As Allah says:

أَفَأَمِنَ أَهْلُ الْقُرَى أَن يَأْتِيَهُم بَأْسُنَا بَيَـتاً وَهُمْ نَأيِمُونَ

أَوَ أَمِنَ أَهْلُ الْقُرَى أَن يَأْتِيَهُمْ بَأْسُنَا ضُحًى وَهُمْ يَلْعَبُونَ

Did the people of the towns feel secure against the coming of Our punishment by night while they were asleep! Or, did the people of the towns feel secure against the coming of Our punishment in the forenoon while they were playing! (7:97-98)

فَمَا هُم بِمُعْجِزِينَ

so that there be no escape for them (from Allah's punishment).

meaning, it is not impossible for Allah, no matter what their situation