18. From here begins the discourse on the confirmation of Tauhid and the refutation of shirk for these were the actual bases of the conflict between the Prophet (peace be upon him) and the disbelievers of Makkah. The line of argument is this: The whole system of the universe is a clear proof that there is One Allah Who is its Creator, Sovereign, Ruler, and Lord and it is a falsehood that there are many gods who are partners in His Kingdom and Sovereignty, or that there is a Supreme God Who has under Him some minor gods to conduct the affairs of His Kingdom. This proof is also based on the preceding verses in which it has been stated that the universe has not been created as a pastime or a plaything, but for a serious purpose and that there has always been a conflict between the truth and falsehood, and falsehood has always been defeated and destroyed.
19. That is, the angels whom the mushriks of Arabia believed to be the children of God and worshiped them as partners in Godhead.
20. That is, they are engaged in His service day and night without grumbling or ever feeling wearied.
21. This question has been posed to bring home to the disbelievers that when they themselves believed that there is no being other than Allah who can give life to inanimate matter, why do they then acknowledge other deities besides Allah?
22. This concise sentence contains two arguments:
(1) The obviously simple argument is that no institution, no household, not to speak of the vast universe containing multitudes of countless distant stars, can function smoothly and properly, if it has two masters.
(2) The deeper argument is that the system of the whole universe, including that of the earth, is functioning according to a universal law. It could not work so even for a moment, if there had been no proper proportion, balance, harmony and coordination between the different powers and countless things. This is a clear proof that there is a universal and all powerful law and system which binds and forces these powers and things to cooperate and coordinate between themselves with a perfect proportion and harmony and this could not have happened if there had been different independent rulers. The existence of such a system is itself a clear proof that there must be One All Powerful Manager and Administrator governing and ruling the entire universe. For further details, please see (E.N. 47 of Surah Bani-Israil).
23. That is, The Sovereign of the whole universe.