1. Istihlak
1.1. Extreme dilution
1.2. Liquid in small quantities are mixed with large mediums until they lose the properties of the liquid
1.3. Example - a drop of wine in a bucket of water that lose their properties, its halal to drink and used as wudhu
2. Al-urf/ al uruf / A'dah
2.1. Repetition or recurrent practice of individual or group of individuals(habits of individual)
2.2. Condition
2.2.1. Must represent a common and recurrent phenomenon
2.2.2. Be dominant in the sense that it is observed in all or most of the cases to which it can applied
2.2.3. Be in the practice at the time of transition
2.2.4. Nor violate the text wether al Quran or Sunnah
2.2.5. Not contravene the clear stipulation of an agreement
2.3. Type
2.3.1. Urf qawli (verbal )
2.3.2. Urf fi'ili (practical)
2.3.3. Urf al amm (general)
2.3.4. Urf al khass (special)
2.3.5. Urf sahih(valid)
2.3.6. Urf fasid (invalid)
2.4. Roles
2.4.1. Valid criterion for perpose interpreting unclear text of either Quran or Sunnah
2.4.2. Determine of shariah legal rulings
2.4.3. Accepted during prophet life's time since the urf of Arab is not overruled by PM
2.4.4. To avoid hardship towards people
3. Al istihab
3.1. Means escorting or companion ship
3.2. Thecnical meaning fact or rules of law and reason, whose existence and non-existence bad been proven in the past are presumed to remain so,for lack of evidence to establish any chance
4. Istihalah
4.1. Substantial/ complete transformation
4.2. Charged something to something else and The process of chemical reaction that change a element from the original
4.3. Example - wine turn into vinegar
5. Maslahah (benefit )
5.1. One that only give a lot of benefits to its user and not dangerous and can be enjoyed by everyone
5.2. Example - food that is halal toyyiban
5.3. Categories
5.3.1. Dharuriyah ( Basic needs )
5.3.2. Hajiyyah ( Convenience and space)
5.3.3. Tahsiniyyah (perfection)
6. Al ihtihsan
6.1. From root word
6.1.1. To deem something preferable
6.1.2. To consider something good
6.2. No agreement between fuqaha' on one particular definition
6.2.1. Al bazwadi
6.2.2. Al halwani
6.2.3. Al sarakhsi
6.3. Importance
6.3.1. Important to branch of ijtihad
6.3.2. Provider for Islamic law with necessary means to encourage flexibility and growth
6.3.3. Can be used for a variety of perpose