An ayah Proving At-Tawhid

Source: The Learning of the Glorious Qur’an, by Ayatullah Misbah Yazdi page 74.

And your God is one God! There is no god but He, the Beneficent, the Merciful."[Suratul-Baqarah/163]
The claim is stated in this ayah. Some say that it even refers to a proof, but we shall not rely on this aspect.
What is quite obvious in this ayah is that the claim of at-Tawhid is stated, i.e. the Qur'an says that its claim is that "Your God is one God." "La ilaha illallah" is a confirmation of it. When your worshipped one is He, then there will be no other worshipped except Him, "ar-Rahman", or "Rahim" (the Beneficent, the Merciful). Why should these two attributes be mentioned here? There are very delicate explanations in this respect, which we do not want to discuss. We may, however, say that the attribute ""ar-Rahman" (the Beneficent) denotes creation and genetic Lordship. While "ar-Rahim" (the Merciful) concerns man's development and spiritual perfection, which is brought about under the shadow of the Legislative Lordship. The stated claim here is that the Ilah (Allah) and the worshipped are one, and that except Him there is no god, and it is He Who is the "Rahman", the Bestower of existence, and it is He Who is the "Rahim", the Merciful. He takes those who tread upon the road of servitude to Him, to a becoming perfection and a worthy happiness. In the next ayah we read:
"Surely in the creation of the heavens and the earth, the alternation of night and day, and the ships that sail on the sea for that which benefits mankind, and the water that Allah sends down from the sky to revive with it the earth after its death, and spread in it all (sorts of) animals; and the changing of the winds and the clouds made to serve between the sky and the earth; there are signs for a people who reason".[Suratul-Baqrah/164] After making the claim, it says: if you think of those phenomena, you will recognize signs that prove the claim. By deeply contemplating on the ayah, it becomes more obvious when you descern the whole universe, its sky, its earth, its moon, its sun, and the revolving of the earth resulting in the appearance of the day and the night, which is related to the sun.
Let the earth revolve around itself a thousand million times, but there will be no day and night without there being a sun. These phenomena, whether, celestial or terrestrial, are connected to each other.
These movements cause the sun to shine on the seas, where from the clouds ascend to the sky, then, under the effect of the conditions of the weather, they turn once again into rain drops pouring down on the earth, causing plants to grow out of it, and the animals to survive. All these phenomena are related to one another. Neither the sky is separate from the earth, nor the earth from the sky. Other terrestrial phenomena are also connected to each other. By studying these phenomena in general you will find that they are governed by a single, coordinated and harmonious order. They are joined together, and whatever you think of, you will see in it the unity, harmony and order. Consequently, such a universe cannot have many gods, or many creators or many directors, because all its phenomena are connected to one another in creation. The Creator of man is the same One Who has created the earth, the parents and the sperm to create man.
It is not possible to say that man's earth is created by another god, and his parents by a second one and their new born baby by a third. Nor can it be said that the sun is created by someone, while the rain is sent down from the sky by another. What does sending down the water mean? Is it anything other than the sun's sending of its heat onto the oceans, turning their waters into vapour, which rises to the sky, and then, under low temperature and certain conditions, it turns once again into water?
Does rain mean anything other than this? Doesn't it happen by the effect of the sun and some other factors? So, the one who has created the sun and the said factors is the same who brings down the rain from the sky. It is a single order, and it cannot be said that the god of the sun is different from that of the rain. The one who moves the wind, also moves your ships on the sea.
Anyhow, it is the laws of nature that are being utilized to make all that man invents and fabricates. Allah has enjoined and regulated these things, and He is the One Who has created the matter, the human beings, and the metals of which ships and planes are made. He created the brain to enable man to turn the metals into those shapes.
It is He Who created the plane as well as the whole world, directly or indirectly. One cannot say that the creator of the ship and the plane is someone other than the One Who created man and the elements of nature, as without the human brain and the elements of nature the plane and the ship cannot be created.
As a result, a deep contemplation on the world's phenomena will guide you to realize that the universe has a single God, Allah.