When did the spoken Arabic language, which people use today, emerge from the Arabic language?

There is no precise date for the emergence of the colloquial language, but linguists have mentioned that it originated and spread with the mixing of Arabs and non-Arabs after the Islamic conquests. Grammatical errors (laḥn) appeared during the time of the Companions, examples of which include: Umar's rebuke of those who erred in their speech, and his punishment of a scribe who made a writing error, and the story of Abu al-Aswad al-Du'ali with his daughter who erred in grammar. Some researchers believe that the colloquial language emerged during the Mamluk era, but it is more likely that it spread before that, as evidenced by the grammarians' lack of citation of the speech of urban dwellers in the Abbasid era.