Among the Behavior of the Idolators was vowing to Things that Allah had provided for Them to their gods
Allah tells us about some of the heinous deeds of those who used to perform baseless worship of other gods besides Him, such as idols and statues, with no grounds for doing so. They gave their idols a share of that which Allah had provided for them,
(They say: "This is for Allah," according to their claim, "and this is for our partners." But the share of their "partners" is not directed to Allah, while the share of Allah is directed to their "partners"! How evil is that with which they judge) (6:136) That is they assigned a share for their idols as well as Allah, but they gave preference to their gods over Him, so Allah swore by His Almighty Self to question them about these lies and fabrications. He will most certainly call them to account for it and give them the unrelenting punishment in the fire of Hell. So He says,
Even the Punishment of the World is Mercy in Disguise
In the verses cited above, after having mentioned various punishments which could seize disbelievers within this world, it was said in the end: فَإِنَّ رَبَّكُمْ لَرَءُوفٌ رَّحِيمٌ (So, indeed your Lord is Very Kind Very Merciful).
First of all, by using the word: رَبّ (Rabb: Lord) here, the hint given is that all these punishments which overtake human beings in this world are there to warn them as part of the dictates of Divine mercy. After that, by introducing the word: رَءُوفٌ(Ra uf: Kind) headed by the intensifying particle lam) that is, the lam of ta'kid), and thus by placing stress on the fact that Allah Ta’ ala was Very Kind and Very Merciful, the hint given was that warnings sent during the life of the world were, in reality, called for by His intrinsic Kindness and Mercy so that heedless men and women would learn from the warning and correct their deeds (before comes 'the last spasm of mass extinction' they themselves are talking about at the closing of the twentieth century, but are still not ready to learn, believe and correct).
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 56–59
From time immemorial, whenever a man finds himself in such trouble that he is absolutely helpless, he starts remembering God. Even polytheists and others who deny the truth behave in this way. This shows that the concept of God is embedded in human nature. When man has no further recourse, he turns at last to God. But strangely, man is so neglectful that when he is relieved of his trouble, he once again becomes preoccupied with the remembrance of his imaginary gods and attributes the benefit received by him to somebody other than God. Satan has introduced different types of false rites among the general people in order to perpetuate and strengthen their belief that imaginary gods are worthy of worship. One of them is to set apart a share of their income for them. Such ceremonies are a sort of falsity in the world of God, because this amounts to giving thanks to entities other than God for the benefits received from Him.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.