Allah is One and Justice Prevails due to Him

Quran 3:18:

Allah witnesses that there is no deity except Him, and [so do] the angels and those of knowledge – [that He is] maintaining [creation] in justice. There is no deity except Him, the Exalted in Might, the Wise.

1. Regarding “Allah (God) witnesses”, the authors of the Study Quran write:

“God is the supreme witness in that He was when there was nothing else with Him (as is said in a well-known ḥadīth, “God was and there was nothing other than Him”), and He thus has most right to be called a witness (R). God is spoken of as Witness throughout the Quran; see, for example, 5:117: And Thou art Witness over all things. God bears witness along with the angels in 4:166: God Himself bears witness to that which He has sent down unto thee . . . and the angels bear witness.”

2. and [so do] the angels and those of knowledge:

The following excerpt is taken from “The Quran with Annotated Interpretation” by Ali Unal pg. 161 note 3:

“Everything in the universe, from the minutest particles to the most expansive galaxies, and every event that takes place in it, bears decisive evidence of the existence and oneness of God. For with a thing’s coming into existence, with its life and particularities, and with the function it fulfills in the general network of existence, every creature and every object points to a single deity who has absolute and infinite Attributes, including, in particular, Knowledge, Power, and will.”

3. [that He is] maintaining [creation] in justice

The followig excerpt is taken from “Tafsir as Saranbi” pg. 75-76:

“In the next part of the ayah Allah (swt) says “maintaining qist ”. Here Allah (swt) is telling us that He (swt) is the One Who is maintaining qist throughout His (swt)’s creation. This word qist is difficult to translate into a single English word. It gives meanings of “justice”, “equity”, and “balance”. The fact that Allah (swt) is maintaining qist throughout the creation is
true on countless ways. Just look at anything around you and you will see how Allah (swt) is maintaining qist in that thing. Look at our planet earth, Allah (swt) is keeping it at the perfect distance between the sun so that it does not become too hot or too cold. We know that if the earth were to go to close to the sun then it would become too hot to support life and if it were to go too far away then it would be too cold to support to life. Allah (swt) keeps it at the perfect distance between the sun, so that the balance and equity is achieved for life to exist. This is one way in which Allah (swt) is maintaining qist. In addition to the distance from the sun, there are
several other conditions that must be achieved in order for life to exist. Examples of these are the presence of the correct combinations of oxygen, carbon and other chemicals, the presence of the right amount of gravity, the right amount of humidity and pressure, and many more factors
that need to be in perfect balance for even one organism of life to exist. Allah (swt) ensures that all of these are present in the right amount so that life on this planet can exist. After we look at the world around us we can even look at our own selves, there are several balances that need to
be achieved throughout our body for us to live and for us to function. Our heart must pump the correct amount of blood, our lungs must take in the right amount of air, our pancreas must produce the right amount of insulin, our blood must flow at right pressure. If any of these balances are not achieved, we would not be able to live. Who is it that is maintaining this balance within ourselves? It is only Allah (Swt) Who maintains balance and equity within ourselves, and throughout this universe so that all of creation can exist.

References:

Unal, Ali (2006). The Quran with Annotated Interpretation in Modern English. (p. 161, note 3) http://www.islamicweblibrary.com/wp-content/uploads/2020/07/The-quran-with-annotated-interpretation-.pdf

 Nasr, Hossein (2015). Study Quran. http://www.islamicweblibrary.com/wp-content/uploads/2020/04/TheStudyQuran.pdf

As Saranbi, Abduraheem (2019). Tafsir As-Saranbi. (p. 75-76). https://ia800704.us.archive.org/16/items/surah-baqarah-quran-tafsir-org-saranbi pdf/surah%20baqarah%20quran%20tafsir%20org%20saranbi%20pdf.pdf