Wanazuoni waliokubali 'Urf walisema: 'Urf unaweza kuwa Swahiih (sahihi) na unaweza kuwa Faasid (potofu). Swahiih ni ule ambao hauendi kinyume na Shar'a, ilhali Faasid ni ule unaoenda kinyume na Shar'a. Mfano wa Faasid ni familia fulani kuzoea kuogelea pamoja katika mabwawa ya kuogelea huku wanaume na wanawake wakichanganyika, au wanawake kutoka nje ya nyumba zao bila mavazi ya Kishar'i, au wanaume na wanawake kucheza pamoja kwa duara moja katika harusi au sherehe za Eid. 'Urf As-Swahiih ambao haupingani na Shar'a umechukuliwa na baadhi ya wanazuoni kuwa ni Daleel ambayo Faqiih au Mujtahid hutumia kama muongozo wa kufikia Ahkaam (hukumu) za baadhi ya mambo halisi ambayo hayana maandiko yake. Kwa hiyo, kwa maoni yao, inawakilisha Masdar (chanzo) miongoni mwa Masaadir (vyanzo) vya kutunga sheria kama Al-Qiyaas na Al-Ijmaa'. Baadhi yao wameichukulia kuwa ni Daleel inayotumika kuongoza kuelewa maana iliyokusudiwa ya maandiko ya Shar'iyah na kutokana na maneno (Alfaazh) ya pande zinazoingia mkataba.

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.

Baadhi yao pia wamelitegemea jambo hilo ili kubainisha ukomo (Takhsees) wa maneno ya jumla ('Aamm) katika baadhi ya misemo ('Ibaaraat), kuweka mipaka (Taqyeed) ya misemo isiyo na masharti (Mutlaq), na kulifanya kuwa hukumu kwa baadhi ya hali, yaani kukubali kauli ya mmoja wa pande zinazozozana pale ushahidi (Bayyinah) unapokosekana kwa upande mmoja.

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.