Kalāmullāh (the Speech of God) is the attribute of Allah that is eternal in His Essence and in no way resembles the speech of created beings. Just as the reality of His Essence is unknown, so too is the reality of this attribute unknown: its nature can only be apprehended through affirmation. As some have said: the kalām (speech) of Allah is command, prohibition, information, promise, and threat. Allah Most High commands, prohibits, informs, promises, threatens, praises, and censures. (Taʿarruf, 18)
The kalām (speech) of Allah, in its entirety, whether it pertains to the words themselves, or to the meanings comprehensible to His servants—be it through revelation, spoken word, or otherwise—is, inasmuch as it indicates these, a manifestation of His knowledge. For the kalām of Allah, in summary, is a single essential attribute. (Insān, I, 50)