The word “Mutakallim” has not been used in the Qura’n but the deed that proves is mentioned like “God talked to Moses” verse 164 of Surah Nisaa. Or in verse 143 of Surah A’raf and this is why Moses became famous as the man who talked with God.
The terms “Kalam Allah’ and Kalami have been used thrice and once respectively in the Qura’n. (1)
The terms “The words of your God” and “The word of God” can be found in the Qura’n (2) and we learn that one of the attributes of God is that He is eloquent. Qaushaji says, not only the Muslims all people of all religions believe that God is eloquent though there is a difference of opinion about the style of eloquence.