Muslims (in general) and theologians (in particular) have agreed that “as-Sadiq”, the Truthful One, is one of His Attributes although they have differed about how to prove it. What is meant by His being Truthful is that His speech is above the stain of falsehood. Since we have opted to regard “speech” as an operative attribute, truthfulness in speech will be similar to it. But if describing someone as being truthful, it means applying an operative attribute, actually standing through Allah, the Praised One; describing Him is best done likewise.
One can produce the evidence about His truthfulness by saying that lying is abominable by reason, and the most Praised One is above anything which reason regards as an abomination. The evidence is based on goodness and ugliness, this is a matter realized by reason. Regardless of incidents and obstacles, a thing is likewise judged as being good or ugly. This principle is the important matter that divided logicians into two groups.
If we take the positive aspect in that principle, where the truth is, it proves that the most Praised One is truthful. But the Asharis, who deny both what is rationally good or ugly, describe the most Praised One as being truthful. They once seek evidence from falsehood being a deficiency, while it is impossible for Allah to be deficient, and once by saying that the Sharia has told us that He is truthful, yet both evidences are scratched off!
As for the First, had we advocated rational goodness and ugliness, it will be impossible to attribute a shortcoming to Allah, Praised is He, in the aspect of the Self and the action. His own Self is above shortcomings, and so is His action, such as speaking. But if we deny that principle, there is no evidence of the impossibility in finding fault with Allah, Praise belongs to Him, with regard to His actions although applying shortcomings to His own Self is absolutely impossible.
For this reason, the Asharis say that He, Praise belongs to Him, can be unfair, an oppressor, and the same applies to the rest of abominable things, although these things are not done by Him by token of His telling us so.
As for the Second, since proving His truthfulness legitimately depends on the truth in what the Prophet says, and his truthfulness is proven only if Allah, Praise belongs to Him, testifies to his being truthful. If the most Praised One stopped testifying for the truthfulness of the Prophet (peace with him and his progeny), the reversal would then be binding.
For this reason, there has to be a definitive evidence behind the Sharia and the revelation testifying to His being truthful and does not lie, the most Praised One that He is.
There is another evidence to which some Mutazilites pointed out. It is summed up by saying that His lying contradicts the interest of the world because if lies become possible in the speech of the most Exalted One, there will be a removal of faith in His telling us about the conditions of the life hereafter, and this means abandoning countless benefits.
What is the most fitting is obligatory on Him, the most Exalted One, and He cannot violate it. What is meant by its being obligatory is that reason realizes that His position, the most Praised One, in this regard necessitates choosing what is best and leaving everything else.1
But the evidence is based on the principle set by the fairness criterion of realizing what is good and what is ugly while discarding all things that are incidental or obstacles. It is then that what is best and most fit is realized, or what is suitable and what is not, and it will be realized that what is best and what is good must be preferred over others. For this reason, there can be no other evidence.
All this applies if we say that His speech is one of the operative attributes. But if we interpret it as being self-speech, as the Asharis have advocated, as you have already come to know, it is not outside the frame of knowledge, freewill, hatred, etc. At that juncture, the truth of His speech will mean that His knowledge is true, and the truth of knowledge cannot be interpreted by any way other than agreeing with the reality. As for the truthfulness of the freewill and of hatred, he does not provide a reason for them. At any rate, truthfulness according to the Asharis will then be one of the self-attributes, not the operative ones.
- 1. Sharh al-Qawshaji, p. 320.