Ibn Battah (d. 387H) said regarding the emergence of what became the view of the Kullaabiyyah and Ash'ariyyah from its Jahmee roots, in his "Ibaanat ul-Kubraa" in the book "ar-Radd 'alal-Jahmiyyah" (1/317-318):

Which translates as:

Chapter: Mention of the Lafdhiyyah and Warning From their Opinion and Their Sayings

Know, may Allaah have mercy upon you that a faction amongst the Jahmiyyah, out of the conniving of their hearts, and the vileness of their opinions and the repugnance of their desires believed that the Qur'an is created. And they alluded to that with an innovation they invented out of deception and misleading of the common folk, [all] in order to conceal their kufr, seeking to obscure their deviation from the one whose knowledge was little and whose disposition was weak. So they said:

The Qur'an that Allaah spoke with and said, that is the speech of Allaah, not created, and as for that which we recite and read with our tongues and which we write in our copies [of the Qur'an] is not the Qur'an which is the Kalaam of Allaah. This is only a hikaayah (quotation, narrative) of that. So what we read is a hikaayah (quotation, narrative) of that Qur'an with our own words (alfaadh), and our verbal expression (with our words) is created.

So they became subtle in their kufr and they used deceitful means in order to enter kufr upon the common folk with the most obscure way, and the most minute [in detail] of madhhab, and the most hidden aspect.

But that was not hidden, by the praise of Allaah, and from Him, and the goodness of his tawfeeq (granting of success) upon the great Scholars, the intelligent critics, until they [the Scholars] rejected as false what they [the Jahmites] fabricated and they unveiled the cover from the repugnance of what they concealed.

So their kufr and deviance became apparent to both the distinguished and the common folk. And the one who who was wise to that and knew where the repugnance lay in [the saying of the Jahmites] was the Shaykh, the Saalih (righteous), and the Imaam, the Scholar, the intelligent one, Abu Abdullaah Ahmad bin Muhammad bin Hanbal - may Allaah have mercy upon him. And the clarification of their kufr was manifest and clear in the Book of Allaah, the Mighty and Majestic, and the Sunnah of His Prophet (sallallaahu alayhi wasallam).

And this viewpoint of this faction of Jahmites, as we can see, is one which the saying of the Kullaabiyyah, Ash'ariyyah derives from - save that the Kullaabiyyah called what they said was the uncreated Qur'aan to be the "Kalaam Nafsee" (the "meaning" that resides with the self of Allaah from eternity), whereas these Jahmiyyah Lafdhiyyah did not speak with that, and nor did these Lafdhiyyah deny that Allaah spoke in reality (with letter and voice) - they simply incorporated their belief that this Qur'an in our presence, in letter and word, is created within the statement "My recitation of the Qur'an is created".

The Kullaabiyyah said that the Qur'aan that we have in our possession, whose words we recite, memorize and hear, that it is created, and it is a "hikaayah" (quotation, narrative) and the Ash'ariyyah said it is an "ibaarah" (expression) - and they don't affirm for Allah the "Kalaam" which is correctly and properly defined in the language of the Qur'an and the language of the Arabs as the combination of the "ma'naa" (meaning) and the "lafdh" (wording, expression) together. Rather, they say Allaah's "Kalaam" is only the "meaning" - and this bid'ah was unknown until Ibn Kullaab originated it and Abu al-Hasan al-Ash'ari followed him in, as has been mentioned by the likes of Abdul Kareem ash-Shahrastani (d. 548H), himself an Ash'ari, who said in Nihaayat ul-Aqdaam (p. 177), whilst noting that ash-Shahrastani's statements in characterizing the views of the Salaf are not entirely accurate and precise, but there is enough in what he has said that approximates to what is correct:

So al-Ash'ari innovated a third saying and judged with the emergence of the letters, and this is the destruction of the ijmaa' (concensus) and he judged that what we read is Allaah's speech only metaphorically (majaazan) not in reality (haqeeqatan) - and this is pure innovation. Why did he not (simply) say that the revelation mentions that what we read and write is the Speech of Allaah without (him) delving into its kaifiyyah (how it is) and its haqeeqah (its reality) - just like in the revelation many attributes have been mentioned such as Face, Two Hands and other than them from the sifaat Khabariyyah.

Here he is saying that al-Ash'ari broke the Ijmaa' and innovated a third saying, which is that the Qur'an is said to be Allaah's speech only "metaphorically", since their view was that Allaah's real Kalaam is the "Kalaam Nafsee", and not the letters and words that make up the Qur'an, and that Allaah does not speak with letter and Voice. Ash-Shahrastani is in error here because it was Ibn Kullaab and the Kullaabiyyah who originated this view and not al-Ash'ari himself.

And Ibn Taymiyyah said in "Majmoo ul-Fataawaa" (6/528):

And as this is known with Ahl us-Sunnah wal-Hadeeth, then it is also the saying of all of the sects of the Ummah, for the majority of all of the various factions say: "Allaah speaks with a voice" alongside their dispute[s] regarding whether His speech (Kalaam) is created (or not)? And is it established with His Self (or not)? And whether it is eternal (qadeem) or recent (haadith)? And whether He has never ceased being "one who speaks when He wills" (or not)?

For this (that Allaah speaks with a voice) is the saying of the Mu'tazilah, Karraamiyyah, Shee'ah, most of the Murji'ah, Saalimiyyah, and other than them from the Hanafiyyah, Maalikiyyah, Shaafi'iyyah, Hanbaliyyah and Soofiyyah.

And there is not from the factions of the Muslims anyone who rejected that Allaah speaks with a Voice (Sawt) except Ibn Kullaab and whoever followed him.

And it is for this reason that Imaam Ahmad condemned the likes of al-Haarith al-Muhaasibee and Hussain al-Karaabeesee because they started speaking with the speech of Ibn Kullaab on this issue.

But returning to the saying of Ibn Battah (and that of Ahmad bin Sinaan al-Waasitee - see here) it is clear and apparent that the roots of the Ash'arite position are found in this faction of people whom the Salaf described with disbelief, deception, treachery, plotting, conniving, repugnance, vileness and the likes.

So all praise is due to Allaah who made the saying of Ahl us-Sunnah wal-Jamaa'ah to be based upon the Qur'an, the Sunnah, and the Ijmaa' of the Righteous Salaf which is that Allaah has always been "one who speaks" (mutakallim), with speech being an attribute of the essence, just like ilm (knowledge) hayaat (life), sam' (hearing) and basr (seeing), and that Allaah also speaks as and when He wills, however He wills, His speech being tied to His will (mashee'ah) and power (qudrah). And alongside all of that, His speech is not created, and the Qur'an is Allaah's speech, He spoke it, and it is uncreated, and that there is only one Qur'an (not two Qur'ans), and whether it is recited, heard, memorized or written, it is, in letter and word, the uncreated, spoken word of Allaah.

And all praise is due to Allaah who made the saying of the Jahmite Ash'arites (of two Qur'ans - see here) to be based upon the sayings of the lowly, vile, despicable, Jahmites of old, the Lafdhiyyah Jahmiyyah who were not seen in the eyes of the Righteous Salaf except as conniving plotters, repugnant, treacherous, deceiving, surmising liars, utterers of kufr - who after being subdued by the likes of Imaam Ahmad in their saying that the Qur'an is created - came with their saying of "lafdh" (my recitation of the Qur'an is created) with a view to arrive at their saying that this Qur'an we have present with us, written, heard, memorized, recited, in letter and word, is created and that there are two Qur'ans, one that was not revealed, and one that was revealed, which is the created Qur'an!

And it is for this very reason that you will see the Jahmite Ash'aris of today and the fake Pseudo-Hanbalis (Sufi Ash'aris posing as Hanbalis) saying:

Hey just say "the Qur'an is Allaah's Speech, not created" but don't go any deeper than that, as there is no benefit in delving these issues and it just causes splits.

And this is from the makr (conniving) of their hearts, and their attempt to conceal a saying that amounts to kufr which is that this Qur'an we have with us, is created. They know full well that their creed is derived from the Jahmite doctrine of al-lafdh, with the Kullaabiyyah being those who developed this doctrine into the doctrine of "Kalaam Nafsee" - so beware of these Jahmites for their deception knows no limits!