Mawlana Ashraf Ali Thanwi
Regarding imkān al-kadhib, one scholar gave a speech that gave rise to some doubt [in the questioner]- namely that the attribute of “speech” (kalām) for Allah is eternal and all His attributes are characterized by perfection whereas lying (kadhib) is a defect (naqs) and flaw (`ayb). Being transcendent from it is necessary (daruri). Thus, the attribute of the attribute (sifat ka sifat), meaning truthfulness (sidq) [in this case], will be eternal also and so it’s opposite is not possible. [Allah’s] power has no relation over these attributes because power relates to the possible (mumkināt) and the attributes [of Allah] are eternal. His speech being truthful eternally and everlastingly is necessary for the reason that all the attributes are ones of perfection. A flaw is not poss ible within it and thus lying is not-possible.
Regarding the matter of possibility and impossibility, then there is no doubt in the exquisiteness and reality of the statement [above], but it relates wholly to the self-speech (kalām nafsī) [of Allah]. Thus, at this level the intrinsic necessity of truthfulness (sidq) and the intrinsic impossibility of lying (kadhib) is something no one differs on.
Rather, the argument is concerning uttered-speech (kalām lafdhī) when it is an act (af`āl) and created (makhlūq), which is the position of the Maturidis. Therefore, the above statement does not apply here. Yet the act being a creation necessitates power (qudrat) over it and power is always associated with opposites due to which the linkage of such qudrat over truthfulness.