The Way of Establishing the Attribute of Speech for Allah from the Basmalah

Honorable Shaykh! Some scholars have mentioned establishing the attribute of speech for Allah from the Basmalah. What is the basis for this?
Because Bismillah al-Rahman al-Rahim is from the speech of Allah (Mighty and Majestic), for it is a verse from the Book of Allah, and the Book of Allah (Mighty and Majestic) in its entirety is the speech of Allah.By the saying of Allah (Blessed and Exalted is He): [At-Tawbah: 6] And it is known that the intended meaning of the verse is: until he hears the speech of Allah from its reciter,For it is impossible that the intended meaning is: he hears the speech of Allah from the One who speaks it, who is Allah (Mighty and Majestic).