What is the evidence for gharib hadith being usable in fiqh?

Question

I performed an analysis on the hadith in Bukhari and came to the conclusion that most hadith (over 90%) are Gharib (single independent chain).

I then learned that a Gharib is not necessarily weak because the conditions for a hadith being authentic do not take into consideration the number of independent chains of narrators.

I also learned a little bit about Imam Shafi' and his debates with Ahl ul Kalam, Mu'tazila etc. regarding the authority of Ahad hadith.

I am curious to know if someone can summarise the opinions of past scholars on Ahad (Gharib, Aziz, Mashur) hadith being authoritative in fiqh.

It seems odd to me because in general Islam requires at least 2 witnesses for most matters. So what is the Quranic evidence for accepting a hadith by a single narrator? I say Quranic evidence because if we were to use hadith it would be circular reasoning.

Answer 1

The following are among the verses which scholars have used as evidence for accepting Ahad narrations (when they fulfill certain criterion regarding the transmitters and the content):

• The verse of Surah at-Tawbah:

  وما كان المؤمنون لينفروا كافة فلولا نفر من كل فرقة منهم طائفة ليتفقهوا في الدين ولينذروا قومهم إذا رجعوا إليهم لعلهم يحذرون

  And it is not for the believers to go forth [to battle] all at once. For there should separate from every division of them a group [remaining] to obtain understanding in the religion and warn their people when they return to them that they might be cautious.

  ^{— Quran 9:122 ; Tafsir al-Qurtubi}

  This verse teaches that a group from every community should learn religion and then educate others among their people when they return from Jihad. This in turn is proof that the report of a small number can be accepted as evidence of Islamic rulings. Further such a group is formed by even just one person the evidence of which is:

  إن نعف عن طائفة منكم نعذب طائفة

  If We pardon one faction of you - We will punish another faction

  ^{— Quran 9:66}

  This verse was revealed about three individuals. The "group" that was forgiven was one person.

  وإن طائفتان من المؤمنين اقتتلوا ... فأصلحوا بين أخويكم

  And if two factions among the believers should fight ... so make settlement between your brothers.

  ^{— Quran 49:9-10}

  This verse was revealed about the fight between two individuals. The evidence of which is the dual أخويكم, so each "group" was one person.

• The verse of Surah al-Ahzab:

  واذكرن ما يتلى في بيوتكن من آيات الله والحكمة إن الله كان لطيفا خبيرا

  And remember (mention) what is recited in your houses of the verses of Allah and wisdom.

  ^{— Quran 33:34 ; Tafsir al-Qurtubi}

  Wisdom means the sunnah. This verse instructs the wives of the Prophet to preach what they learn from the Prophet ﷺ in their homes. This in turn proves that what they report would be acceptable as evidence of Islamic rulings. And such a report would obviously be singular as it occurred in their individual private homes.

• The verse of Surah al-Hujurat:

  إن جاءكم فاسق بنبإ فتبينوا أن تصيبوا قوما بجهالة

  If there comes to you a disobedient one with information, investigate, lest you harm a people out of ignorance.

  ^{— Quran 49:6 ; Tafsir al-Qurtubi}

  This verse instructs us to independently investigate the report of a Fasiq before accepting it. This implies that doing so is not required on the report of an 'Adil, as otherwise there would be no need to specify the status of the informer.