Here Allah mentioned a debate with the idolators, refuting a false notion they have over their Shirk and the things that they prohibited. They said, surely, Allah has full knowledge of the Shirk we indulge in, and that we forbid some kinds of wealth. Allah is able to change this Shirk by directing us to the faith, - they claimed - and prevent us from falling into disbelief, but He did not do that. Therefore - they said Allah indicated that He willed, decided and agreed that we do all this. They said,
("If Allah had willed, we would not have taken partners (in worship) with Him, nor would our fathers, and we would not have forbidden anything.") Allah said in another Ayah,
Mentioned in the previous verses was how astray the disbelievers of Makkah had gone when they had taken their self-carved, lifeless, insensate idols as partners in the Divinity of Allah as they made them share in animals created by Him and in many other blessings which were bestowed on them. Their transgression went to the limits when they would take out charities from these blessings as an act of worship, setting aside a portion for Allah and another for their idols. Then, they would employ different excuses to take out what belonged to the portion set aside for Allah and put it in the portion reserved for the idols. Similarly, there were many other ignorance-based arbitrary customs which they had given legal status.
The unadulterated missionary call for Truth always stands out as something rather strange. On the one hand, there is the customary religion which enjoys prominence in all social institutions. Centuries of traditions are behind it to lend it weight. On the other hand, there is the call for Truth, which has no time-honoured conventions in its favour. It is difficult, therefore, for people to understand that customary religion, which has such an elevated status and great popularity, will not be to God’s liking. The common presumption is that it has been possible for the customary religion to flourish to this extent because it suited God’s will and pleasure: had it not been so, it would not have spread and endured to this extent. They raise the question of whether God’s favoured religion will be one already enjoying a high status everywhere in this world of God or one which has no standing whatsoever.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.