An existing translation of as-Sa'dee's work titled (رسالة لطيفة جامعة في أصول الفقه المهمة) "A Brief, Concise Treatise Regarding Important Principles of Fiqh" has been used as a basis for these articles with corrections to numerous errors in the translation, improvements and amendments to make the material easier to read and comprehend. This translation was received and published 14 years ago on the Salafi Publications website and is also widely distributed on the web.
Chapter Four: Concerning the Book and the Sunnah
فصل في الكتاب والسنة : أما الكتاب : فهو هذا القرآن العظيم ، كلام رب العالمين ، نزل به الروح الأمين ، على قلب محمد رسول الله- صلى الله عليه و سلم -ليكون من المنذرين ، بلسان عربي مبين ، للناس كآفة ، في كل ما يحتاجون إليه من مصالح دينهم ودنياهم ، وهو المقروء بالألسنة ، والمكتوب في المصاحف ، المحفوظ في الصدور ، الذي "لا يَأْتِيهِ الْبَاطِلُ مِنْ بَيْنِ يَدَيْهِ وَلا مِنْ خَلْفِهِ تَنْزِيلٌ مِنْ حَكِيمٍ حَمِيدٍ" فصلت/42. وأما السنة : فإنها أقوال النبي- صلى الله عليه و سلم -، وأفعاله ، وتقريراته على الأقوال والأفعال.
فالأحكام الشرعية تارة تؤخذ من نص الكتاب والسنة ، وهو اللفظ الواضح الذي لا يحتمل إلا ذلك المعنى ، وتارة تؤخذ من ظاهرهما ، وهو ما دل على ذلك على وجه العموم اللفظي أو المعنوي.
وتارة تؤخذ من المنطوق ، وهو ما دل على الحكم في محل النطق ، وتارة تؤخذ من المفهوم ، وهو ما دل على الحكم بمفهوم موافقة ، إن كان مساوياً للمنطوق ، أو أول منه ، أو بمفهوم المخالفة إذا خالف المنطوق في حكمه ، لكون المنطوق وصف بوصف أو شرط فيه شرط إذا تخلف ذلك الوصف أو الشرط ، تخلف الحكم.
والدلالة من الكتاب والسنة ثلاثة أقسام : دلالة مطابقة : إذا طبقنا اللفظ على جميع المعنى ، ودلالة تضمن : إذا استدللنا باللفظ على معناه ، ودلالة التزام : إذا استدللنا بلفظ الكتاب والسنة ومعناهما على توابع ذلك ومتمماته وشروطه ، وما لا يتم ذلك المحكوم فيه أو المخبر عنه إلا به
As for the Book: It is this Mighty Qur'an, the Kalaam (Speech) of the Lord of the worlds, which the Trustworthy Spirit descended with upon the heart of Muhammad the Messenger of Allaah (sallallaahu 'alayhi wa sallam), that he may be from the warners to the whole of mankind - in the clear arabic tongue - regarding all that they stand in need of with regards to what benefits them concerning their Religion and their world. The Book of Allaah is that which is recited by the tongues, written in the masaahif (copies), and preserved in the hearts, [it is] that which: "No falsehood can approach from before or from behind it, it was sent down from the All-Wise, the One deserving of all praise."[Soorah Fussilat 41:42].
As for the Sunnah: It is the Prophet (sallallaahu 'alayhi wa sallam's) aqwaal (sayings), af'aal (actions), and his taqreeraat (tacit approvals) of the sayings and actions (of others).
The ahkaamush-shar'iyyah (Sharee'ah rulings):
- Are sometimes taken from a definite text (nass) of the Book and the Sunnah; which is defined as that clear text (whose meaning is apparent and plain) and which does not afford except that single meaning.
- Sometimes it is taken from the dhaahir (apparent) meaning of them both (the Book and the Sunnah); which is defined as that which is indicative of (that ruling) [which is apparent] through the generality of wording and meaning.
- Sometimes it is taken from the mantooq (that which is expressed); which is defined as being that which is indicative of the ruling through (clear) expression (of the ruling).
- Sometimes the ahkaamush-shar'iyyah are taken from the mafhoom (that which is understood from the wording); which is defined as that which is indicative of the ruling by way of a meaning that concurs (with the text in which it occurs) in such cases where the mafhoom is equal to or stronger than the mantooq. Or by an opposing meaning (mafhoom al-mukhaalafah) if the mafhoom differs from the mantooq in its ruling due to the mantooq being linked to a wasf (attribute) or a shart (condition), in the absence of which the ruling no longer applies.
The dilaalah (how something is an evidence for something else) in the Book and the Sunnah are of three kinds:-
 Dilaalah Mutaabaqah: this is where we apply the word to indicate the entirety of the meaning (it applies to).  Dilaalah Tadammun: when we employ the wording to indicate one (part) of its meaning.  Dilaalah Iltizaam: where we employ the wording of the Book and the Sunnah and their meanings to what are the necessary consequences (tawaabi'), completing matters (mutammimaat), and conditions (shuroot) of (that word); and (likewise) that which the matter being judged with or being informed of cannot come about, except by way of it.
 The meaning of these three types of evidences becomes more clear when we look at physical example and apply th three types of evidences to it. So when we say "We have a house (bayt)", the the word "bayt (house)" contains three types of indications of evidence: a) We understand from the word "bayt" that it indicates the entire house by way of the evidence through mutaabaqah (agreement of word with entire meaning), and b) the word "bayt" indicates the men's sitting room on its own, or the washroom on its own by way of evidence through "tadammun" (inclusion) because these things are a part of the house, and when a word indicates a part of its (overall) meaning, it is "dilaalaah al-tadammun" (a word providing evidence to a part of its meaning through the route of inclusion), and c) the word "bayt" indicates that there is a foundation (beneath the house) through the route of "dilaalah al-iltizaam", since there is no house except that it must have a foundation beneath it - so the foundation is indicated by the word "bayt" because it is from what follows on from a house, and from its requirements and necessities. From this we understand how Shari'ah texts provide evidence to certain things, they can be through mutaabaqah, tadammun or iltizaam. This is important to grasp because it allows us to see how Scholars have derived rulings from texts and the particular route of evidence that has been used from a given text.