Hoja ya kufanya istidlaal kutoka katika Kitaab na Sunnah inategemea kujua lugha ya Waarabu, na kujua mgawanyo wake, kwa kuwa zimeteremshwa kwa lugha ya Waarabu. Allah Ta'ala amesema: {Kwa lugha ya Kiarabu iliyo wazi} Surat Ash-Shu'araa', aya ya 195. Kwa hiyo ni lazima kutaja mijadala ya lugha na mgawanyo wake. Na yanayojadiliwa katika mgawanyo wa kauli ni yale tu yanayohusiana na kutoa hukumu, kwa kuwa hakuna haja ya kujadili zaidi ya hayo katika usuli al-fiqh. Zaidi ya hayo, Kitaab na Sunnah vyote vimegawanyika katika khabar (habari) na inshaa' (utungaji). Hata hivyo, mwanachuoni wa usuli huangalia inshaa' pekee bila khabar, kwa kuwa katika mara nyingi hukumu za kisheria hazithibitishwi kupitia khabar. Kutokana na hapa, kauli katika Kitaab na Sunnah imegawanyika katika: amri (amr) na katazo (nahi), jumla ('aam) na maalum (khaass), isiyofungwa (mutlaq) na iliyofungwa (muqayyad), iliyofupishwa (mujmal) na iliyofafanuliwa (mubayyan), kufuta (naasikh) na kufutwa (mansuukh). Kwa hiyo ni lazima kukusanya mjadala wa lugha, pamoja na mgawanyo huu wa Kitaab na Sunnah, ili uweze kufanya istidlaal kutoka Kitaab na Sunnah kwa kupata hukumu za kisheria.

The inference from the Kitaab and the Sunnah depends on knowing the language of the Arabs, and knowing its divisions, because they are sent down in the language of the Arabs. Allah Ta'ala said: In an Arabic clarifier tongue) 195 Surat Al-Shu'araa', therefore it is inevitable to mention the discussions of the language and its divisions. And what would be discussed from the divisions of the saying is that which is related to the derivation of the verdict only, since there is no need to discuss other than that in usoul al fiqh. Further more both the Kitaab and the Sunnah are divided into tiding (khabar/news) and composition (inshaa'), however the scholar of the usoul ponders to the inshaa' only without the khabar because in most cases the verdicts are not established in it, from here the saying in the Kitaab and Sunnah is divided into: command (amr) and prohibition (nahi), general ('aamm) and special (khaass), unrestricted (mutlaq) and limited (muqayad), summed up (mujmal) and detailed (mubayan), abrogator (naasikh) and abrogated (mansoukh). Accordingly it is inevitable to summing up a discussion in the language, and in these divisions of the Kitaab and the Sunnah, to be able to infer from the Kitaab and the Sunnah over the shari'ahi verdicts.