Al-Isra: (23) And your Lord has decreed...

Know that when the first verse mentioned the greatest pillar of faith, it was followed by mentioning the rituals and conditions of faith, which are of several types.

The First Type: That a person be occupied with the worship of God Almighty, and that they refrain from worshipping anyone other than God Almighty. This is what is meant by His saying: {And your Lord has decreed that you worship none but Him}.

There are two discussions concerning this:

The term Qaḍā’ (decreed/judged) means an absolute, decisive judgment that does not accept abrogation. The proof for this is that if one of us commands another to do something, it is not said that he qaḍā (decreed) upon him. However, if he commands him with an absolute command and judges that matter upon him decisively and definitively, then it is said: qaḍā upon him. The word Qaḍā’ in its linguistic origin refers to the completion and finality of a matter.

It is narrated from Maymun ibn Mihran on the authority of Ibn Abbas that he said: In this verse, the original reading was Wa waṣṣā rabbuka (And your Lord enjoined), and one of the wāws adhered to the ṣād, so it was read as {Wa qaḍā rabbuka} (And your Lord decreed). He then said: If it were about decree (qaḍā’), no one would have disobeyed God, because opposing God's decree is impossible. This is narrated from him by Al-Ḍaḥḥāk and Sa'īd ibn Jubayr, and it is the recitation of 'Ali and 'Abdullah.

Know that this view is very remote because it opens the door to the possibility that alteration and change have affected the Qur'an. If we permit that, security regarding the Qur'an would be lifted, rendering it no longer a proof. Undoubtedly, this is a grave slander against the religion.

We have already mentioned that this verse indicates the obligation of worshipping God Almighty and prohibits the worship of anyone other than God Almighty. This is the truth. This is because worship ('ibādah) is defined as an action encompassing the utmost reverence, and the utmost reverence is only fitting for the one from whom the utmost bestowal of favor (in'ām) originates. The utmost bestowal of favor is the giving of existence, life, power, desire, and intellect. It has been established by proofs that the Giver of these things is God Almighty and no one else. Since the Bestower of all blessings is God and no one else, it is inevitable that the one deserving of worship is God Almighty and no one else. Thus, the correctness of His saying {And your Lord has decreed that you worship none but Him} is established by rational proof.

{And lower to them the wing of humility out of mercy, and say, "My Lord, have mercy upon them as they raised me when I was small."}

{Your Lord is most knowing of what is within your souls. If you should be righteous, then indeed, He is to the oft-returning [to Him] Forgiving.}