Ulamolar, ya'ni 'urfni qabul qilgan olimlar, shunday deganlar: 'Urf sahih (to'g'ri) ham bo'lishi mumkin, fosid (buzuq) ham bo'lishi mumkin. Sahih bo'lgani — Shar'ga zid kelmaydigan, fosid bo'lgani esa — Shar'ga zid keladigan 'urfdir. Fosid 'urfga misol: ba'zi oilalarning suzish havzalarida erkaklar va ayollar aralash holda birga suzishga odatlangani yoki ayollarning Shar'iy libossiz uylaridan chiqishi yoki to'y va Hayit bayramlarida erkaklar bilan ayollarning bir doira bo'lib birga raqs tushishi kabilar. Shar'ga zid bo'lmagan sahih 'urfni ba'zi ulamolar fiqh olim yoki mujtahid hukmi yo'q bo'lgan ba'zi voqeliklarning ahkomiga (hukmlariga) yetib olish uchun yo'l-yo'riq sifatida foydalanadigan dalil deb hisoblaganlar. Ularning fikricha, bu qiyos va ijmo' kabi qonun chiqarish manbalaridan (masodir) biri hisoblanadi. Ba'zilari uni Shar'iy matnlarning maqsadini va shartnoma tomonlarining so'zlarini (alfozlarini) tushunishga yo'naltiruvchi dalil deb hisoblaganlar.

The ‘Ulamaa who adopted the ‘Urf stated: ‘The ‘Urf can be Saheeh (correct) and it can be Faasid (corrupted). The Saheeh is that which does not go against the Shar’a whilst the Faasid is that which goes against the Shar’a. The Faasid would be like some families being accustomed to swimming together in the swimming pools whilst the men and women are mixed or women leaving their houses without the Shar’iy dress or like men and women dancing together in a single circle at weddings or Eid celebrations. The ‘Urf As-Saheeh which is not contrary to the Shar’a has been considered by some of the ‘Ulamaa to be a Daleel that the Faqeeh or Mujtahid uses as a guide to arrive to the Ahkaam (rulings) of some of the realities which do not have a text for them. It therefore represents, in their opinion, a Masdar (source) from the Masaadir (sources) of legislation like Al-Qiyaas and Al-Ijmaa’. Some of them have considered it to be a Daleel that is used to guide to understanding the intent of the Shar’iyah texts and from the wordings (Alfaazh) of contracting parties.

Ba'zilari ham uni ayrim ibora (so'z qo'llanishlari)ning ‘Aamm (umumiy) ma'nosini tahsis qilish (Takhsees), Mutlaq (cheklanmagan) ifodalarni cheklash (Taqyeed) uchun va bayyina (guvohlik dalillari) bo'lmagan taraflardan birining so'zini qabul qilish uchun ayrim holatlarga hukm sifatida qo'llaganlar.

Some of them have also relied upon it in order to specify (Takhsees) the ‘Aamm (generalness) of some of the worded expressions (‘Ibaaraat), to restrict (Taqyeed) the Mutlaq (unrestricted) expressions and to make it a Hukm for some of the situations to accept the statements of one of the disputing parties when the Bayyinah (testimonial evidence) is absent from one of them.