أَلَمْ تَرَوْا۟ أَنَّ ٱللَّهَ سَخَّرَ لَكُم مَّا فِى ٱلسَّمَٰوَٰتِ وَمَا فِى ٱلْأَرْضِ وَأَسْبَغَ عَلَيْكُمْ نِعَمَهُۥ ظَٰهِرَةً وَبَاطِنَةً · وَإِذَا قِيلَ لَهُمُ ٱتَّبِعُوا۟ مَآ أَنزَلَ ٱللَّهُ قَالُوا۟ بَلْ نَتَّبِعُ مَا وَجَدْنَا عَلَيْهِ ءَابَآءَنَآ
"Have you not seen that God has put at your service whatever is in the heavens and whatever is in the earth, and that He has poured His favours upon you in abundance, outward and inward? And when they are told, 'follow what God has sent down', they say, 'No, we follow what we found our fathers upon.'"
أَسْبَغَ — root س-ب-غ — it occurs here for the first time in this series. The sense the lexicographers give: to make a thing ample and complete, to cover it without a gap. Dirʿun sābigha — a coat of mail that covers the body entirely.
The picture in the word is worth recording: favour is described not as a heap to be counted but as something that covers.
ظَٰهِرَةً وَبَاطِنَة — "outward and inward". The pair lies on the same axis as wa mā tukhfi'ṣ-ṣudūr, treated at 40/19 in Ghāfir (al-Muʾmin): the seen and the unseen. Here the same distinction is used of favour.
This argument was treated in detail at 43/22-23 in al-Zukhruf (innā wajadnā ābāʾanā ʿalā ummatin), and what was recorded there holds here as well: the objection rests not on the content of what is proposed but on the newness of its source. I rely on that treatment.
And the verse adds a question: a-wa-law kāna'sh-shayṭānu yadʿūhum ilā ʿadhābi's-saʿīr — "even if Satan were calling them to the punishment of the blaze?" That is, the open place in the objection is pointed out: how is it known that everything that comes from the fathers is right?