Abd Al-Raḥmān b. Mahdī reports:

I entered upon Mālik b. Anas when a man was asking him about the Qur'ān. [Imām Mālik] said, “Perhaps you are a companion of  Amr b. ‘Ubayd. May Allāh curse ‘Amr, for he was the one who innovated this bid’ah of Kalām  . If Kalām was knowledge, the Companions and their Followers would have spoken it, like they spoke about the regulations and laws [of Islam]. But [Kalām] is falsehood that leads to falsehood.”

Abul-Faḍl Al-Muqri'Al-Rāzī, Aḥādīth fī Dham Al-Kalām wa Ahlihī p96.
Al-Harawī, Dham Al-Kalām wa Ahlihī no.874.