All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Here, there are two aspects:
1- The language which we speak and it includes the letters of the Arabic language: this language is created.
2- The letters of the Quran are not created.
The scholars say: “The words are the words of the Creator and the pronunciation is the pronunciation of the reciter.”
Ibn Al-Qayyim clarified this in his book As-Sawaa’iq Al-Mursalah; he said: “If it is said: "Are the letters of the Mu'jam (Arabic lexicon) eternal or created?" Then, the answer is that the letter is of two kinds: the letter which is uttered by the creature is created, but the letters of the Quran are not created. If it is said: "How could the same letter be created and not created?" Then the answer is that it is not the same in itself but the same in its kind. This is very much in the same manner that speech is divided into what is created and not created, it is one in kind but not one in itself. In order to clarify this, this entity [the letter] has four ranks: in itself, in one's mind, on one's tongue and in writing. So, the first rank is its existence in itself, the second is its existence in the mind [how a person imagines it], the third is its existence in its pronunciation [how one utters it] and the fourth is its existence in writing [in its written form]...... With regards to speech, its outward existence is what is uttered by the tongue, its existence in the mind is what is in the heart and its existence in writing is its written form. As for its verbal existence, it combines two ranks: the outside rank and the verbal rank. Another point is that the sound that has the act of initiating the speech is like the sound by which one utters it (the speech).... and the speech is attributed to the one who first said it and not to the one who narrates it and conveys it. For example, if one of us says: ‘Actions are judged by intentions’, as a way of reporting it from the Prophet no one would say that this is your statement and your words. It could be said: “You conveyed it in a good manner and said it in a good manner.” Although we know that the one who conveyed it and said it in a good manner is created, this person is intimately related to the origin of the speech itself making it difficult to distinguish between the two. Hence, both parties are wrong: the first considered everything (all ranks of speech) as created and separate and the second considered everything eternal, which is the very Attribute of the Lord because it was He Who spoke it the first time. However, the correct opinion is that of the Imaams of the Muslims, like Imaam Ahmad, Al-Bukhari and the scholars of Hadeeth: that the sound is the sound of the reciter and the words (of the Quran) are the words of the Creator...etc.”
For more beneficial information, please refer to Fataawa 29238, 122436 and 92244.
Allaah Knows best.