Some claim that Allah ﷻ’s attribute of speech is composed of uncreated utterances pronouncing the Arabic words written on the Mushaf. We argue that this impossible, because such pronunciations would exist contingently, and what is contingent depends on a creator to have brought it into existence.
As for proving the contingency of the utterances pronouncing the Arabic words of the Mushaf: this is given that they exist as sequential sounds, emerging one after the other.
For example: when one utters the word “Allah” as found in the Mushaf, the “L” sound is not being uttered when the utterer is uttering the “A” sound, and the “A” sound is not being uttered when the utterer is uttering the “L” sound. This is because the word “Allah” is composed of sequential letters, that are pronounced sequentially. Therefore, each of the “A” and the “L” sounds accepts existence and non-existence. And this is all what we mean by contingent.
For the same reason, all the other utterances pronouncing the Arabic words of the Mushaf, exist contingently.
With the above in mind we say: what exists contingently, depends on an extrinsic specifier to have granted it existence. And this all what is meant by ‘created’.
Thus, those utterances are necessarily created.
And if it is asked: “what then is the relation between the Arabic phrases Muslims recite every day, and Allah ﷻ’s attribute of Speech?”
The response: those Arabic phrases express meanings that were eternally signified by Allah ﷻ, by virtue of His being attributed with Speech. More on the distinction between Self-Speech and the utterances which express it here.
Allah ﷻ created Arabic words which express the meanings that He eternally signified, and made Jibril (عليه السلام) aware of them. Jibril was then commanded to deliver those words to Prophet Muhammed ﷺ. And they have reached us through him ﷺ by mass transmission.
 How Jibril (عليه السلام) was made aware of them is a secondary matter. It could have been that Allah ﷻ created sounds expressing those words to Jibril. It could have been that Allah ﷻ created carvings of those Arabic words onto the Preserved Tablet, which Jibril then read. It could have been some other way.
What is important is to realize that no matter the manner through which Jibril was made aware of those Arabic words, those Arabic words are necessarily created.