His saying: "Nay, but indeed his Lord was ever All-Seeing of him," meaning: that He will resurrect him. Interpretation of Surah al-Inshiqaq from verses 16-25.
قَوْلُهُ: ﴿بَلَى إِنَّ رَبَّهُ كَانَ بِهِ بَصيرًا﴾ أَي: أَنه سيبعثه. تَفْسِير سور الانشقاق من آيَة ١٦ - ٢٥
