Is the statement: "Man cannot think without language, and the quality of his thought is dependent on the breadth of the words he masters, and his language affects his understanding of the universe" correct and does it have proof in the Quran and Sunnah, and what is the relation of this to the Quran being made Arabic?

There are types and fields of thinking that do not require language, for the mind is broader than the tongue. A person may think about things that do not exist or for which no name is known. A young child perceives and thinks before learning language, and a deaf-mute person possesses perception and thought. Even animals have a kind of perception and intelligent thinking. Nevertheless, the breadth and precision of language influence intellectual output, as humans often think in the language they master and use to formulate their output. And His (Allah's) saying, exalted be He: "And We did not send any messenger except with the language of his people to make clear to them," does not indicate that Arabic is the oldest of languages, but rather that it is the best and finest of them.