Although some scholars like those from the Hanafi school accept rationale „Illah‟s, the strongest position is that the „Illah must be from the text. This is because the mind is not capable to determining the reasons for the rules unless they have been revealed by Allah (swt). The „Illah is the daleel which allowed the extension of the rule to a new matter. For this rule to be a Hukm Shar‟i i.e. a valid ruling of the Shar‟iah, it must be taken from the speech (Khitaab) of the Legislator since the definition of Hukm Shar‟i is the speech of the Legislator relating to man‟s actions. Any rule which is not from the speech of the legislator is rejected because it is not revelation (Wahiy) and we are ordered only to follow the Wahiy in our actions. To extend the rule without a textual „Illah would be like extending the prohibition of alcohol to vinegar just because vinegar originates from alcohol. Alcohol is one reality and vinegar is another. One cannot arbitrarily extend the Hukm without the text allowing such an extension. If the text allows it through an „Illah, then this is a valid Hukm Shar‟i, if not then it is a rational judgment which has no value in the Shar‟iah.

This is notwithstanding the fact that man is unable to give judgment on that which he cannot sense. If the Creator did not provide us the reason („Illah) for the legislation of the rule then how can man judge it. Thus, not only is the rational „Illah rejected from the viewpoint of Hukm shar‟i but it is practically impossible for man to give such a judgment in the first place.

Furthermore, the fact that the mind cannot make analogy without a Shar‟i „Illah is aptly demonstrated by the reality of the Shari‟ah rules themselves. For example, we find similar realities are given different Ahkam while different realities are given the same Hukm. The mind can normally make analogy between similar things but the text contradicts this principle: So in the absence of water, of all things dust are sufficient to make Wudhu even though they are two different things. According to the Shari‟ah rules if a baby girl urinates on clothes then the clothes must be washed but if a baby boy does the same then it is sufficient just to sprinkle some water on it. Thus, similarity does not mean the same Hukm just as dissimilarity does not mean a different Hukm. So how can the mind make analogy for the sake of new Ahkam when even the existing Ahkam cannot be rationalised without a Shar‟i „Illah?