Garchi ba'zi olimlar, masalan, hanafiy mazhabi ulamolari, aql bilan topilgan illatlarni qabul qilsalar-da, eng kuchli qarash shundan iboratki, illat matndan bo'lishi shart. Buning sababi shuki, Alloh (SWT) tomonidan vahiy qilinmagan bo'lsa, aql hukmlarning sabablarini aniqlashga qodir emas. Illat esa hukmni yangi masalaga kengaytirishga imkon beruvchi dalildir. Bu hukm Hukm Shar'iy, ya'ni Shariatning to'g'ri hukmi bo'lishi uchun u Shori'ning (Shori' – Alloh) xitobidan olingan bo'lishi kerak, chunki Hukm Shar'iyning ta'rifi – insonning amallariga oid Shoriy'ning kalomidir. Shoriy'ning kalomidan bo'lmagan har qanday hukm rad etiladi, chunki u vahiy emas, biz esa amallarimizda faqat vahiyga amal qilishga buyurilganmiz. Matnda illat bo'lmasdan hukmni kengaytirish, sharob ta'qiqini sirka ga ham yoyishga o'xshaydi, faqat sirka sharobdan kelib chiqqani uchungina. Sharob bir haqiqat, sirka esa boshqa haqiqatdir. Matn bunga ruxsat bermagan holda hukmni o'zboshimchalik bilan kengaytirib bo'lmaydi. Agar matn illat orqali bunga ruxsat bersa, bu to'g'ri Hukm Shar'iy bo'ladi; agar ruxsat bermasa, bu Shariatda hech qanday qadr-qimmatga ega bo'lmagan aqliy hukm bo'ladi.

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.

Bunga qaramay, inson o‘zi sezmaydigan narsaga hukm bera olmaydi. Agar Yaratuvchi hukmni tashri' qilish uchun sababni („illa) bizga bermagan bo‘lsa, unda inson uni qanday hukm qila oladi? Shunday ekan, nafaqat aql bilan topilgan „illa shar'iy hukm nuqtai nazaridan rad etiladi, balki insonning bunday hukm chiqarishi avvalo amalda mumkin emas.

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.

Bundan tashqari, aql Shar'iy illatsiz qiyos qila olmasligi haqiqatni Shariat hukmlarining o'zi yaqqol ko'rsatadi. Masalan, o'xshash narsalarga turli hukmlar berilganini, turli narsalarga esa bir xil hukm berilganini ko'ramiz. Odatda aql o'xshash narsalar o'rtasida qiyos qila oladi, ammo matn bu qoidaga zid keladi: suv yo'q bo'lganda, ikki xil narsa bo'lishiga qaramay, barcha narsalardan tuproq bilan Wudu' qilish kifoya qiladi. Shariat qoidalariga ko'ra, agar go'dak qiz kiyimga siysa, kiyimni yuvish kerak, ammo go'dak o'g'il bola xuddi shunday qilsa, ustiga biroz suv sepish kifoya qiladi. Demak, o'xshashlik bir xil hukmni anglatmaganidek, farqlilik ham boshqa hukmni anglatmaydi. Unda mavjud hukmlarning o'zi Shar'iy illatsiz oqilona asoslanmaydigan bo'lsa, aql yangi hukmlar uchun qanday qilib qiyos qila oladi?

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?