Waislamu kwa ujumla walikuwa wakifanya Taqlīd kwa mujtahidina licha ya tofauti zao, kwa sababu msingi wa tofauti zao ulikuwa ni dalili za Sharī'ah. Hivyo, kuelewa kwa kila mujtahid maana ya khitab al-shaari' (mwelekeo wa Mwenye kutunga Sharī'ah) kunachukuliwa kuwa ni hukmu ya Sharī'ah kwa upande wake na kwa upande wa yule anayemfuata katika Taqlīd. Hii ni kwa sababu khitab al-shaari' ndiyo hukmu shar'i, na kuelewa khitab al-shaari' pia ni hukmu ya Sharī'ah, lakini kwa mtu aliyeielewa na kwa yule anayemfuata katika kuelewa huko. Wale waliofikia kuelewa khitab al-shaari' walikuwa wakifanya Ijtihād. Wale ambao hawakufikia kiwango cha Ijtihād walikuwa wakifuata, katika ahkām (hukmu), wale waliofikia kiwango cha Ijtihād na kufanya Ijtihād. Jambo hilo halikuwa la kumfuata faqih kama mtu binafsi, kama vile jambo hilo si la kufanya Taqlīd kwa madhehebu. Badala yake, jambo ni kukubali hukmu shar'i aliyoitoa faqih kwa kutumia dalili na kuitendea kazi. Kwa kuwa Muislamu ameamrishwa kufuata Sharī'ah tu na kuitendea kazi, na si kufuata madhehebu au mtu, wala kutenda kulingana na madhehebu fulani au kumfuata mtu fulani. Akiweza kufikia hukmu shar'i kupitia Ijtihād yake mwenyewe, afanye hivyo; asipoweza, akubali hukmu aliyoitoa mtu mwingine. Katika zama za mwanzo, mujtahidina walihesabiwa kwa maelfu. Ndiyo maana tunaona kwamba mujtahidina ambao Waislamu walikuwa wakiwafuata hawakuwekewa kikomo cha manne, watano, sita au idadi yoyote ya madhehebu; kwa kweli kulikuwa na madhehebu mengi na mujtahidina wengi. Kila kundi lilikuwa likifuata hukmu zilizotolewa na mujtahid, awe ni wa madhehebu au si wa madhehebu. Kwa mfano, watu wa kawaida wa Kufa walikuwa wakitenda kwa fatwa ya Abu Hanifah na Sufyan al-Thawri, ilhali Shi'a walikuwa wakitenda kwa madhehebu ya Ja'far al-Sadiq. Desturi wa watu wa Makka ulikuwa kufuata fatwa za Ibn Jurayj, watu wa Madina walifuata fatwa za Malik, watu wa Basra walifuata fatwa za ‘Uthman, watu wa al-Sham walifuata fatwa za al-Awza’i, watu wa Misri walifuata fatwa za Ibn Sa’d, watu wa Khurasan walifuata fatwa za ‘Abd Allah ibn al-Mubarak, na baadhi ya watu wa Yemen walifuata fatwa za Zayd ibn al-Husayn. Waislamu wengi walifuata fatwa za Sa’id ibn al-Musayyab, Ibn Abi Layla, ‘Ikrama, Rabi’i Ar-Ra’i, Muhammad ibn Shihaab Az-Zuhri, Hasan Al Basari, Laith ibn Sa’ad, Sufyan Ibn ‘Uyayna, Ishaq ibn Rahawiya, Abi Thawr, Dawud Az-Zahiri, Ibn Shibrima na Ibn Jarir At-Tabari. Kila mmoja wao alikuwa Mujtahid na aliongoza mazhabu. Kila mojawapo ya mazhabu hizi ilikuwa na mbinu maalum ya Ijtihād na ra’i (maoni) maalum katika ahkam. Wengi wa Mujtahidin na Maimamu walikuwa mahakimu na watawala katika nchi. Tofauti kati ya maimamu, mahakimu na watawala zilisababisha tofauti katika ahkam (hukumu), kila mmoja akihukumu kwa maoni yake mwenyewe au kwa maoni ya faqih ambaye maoni yake alikuwa akiyashika. Hali hii ilisababisha kuwepo kwa hukumu tofauti ndani ya dola. Kwa sababu hiyo, kulikuwa na ‘Ulamā ambao waliona wazi umuhimu wa kuunganisha hukumu zinazotolewa, na walitaka Khalifah atoe amri kwa watu kuifuata. Wakati huo, baadhi ya watu waliojua hali ya jamii walikuwa na maoni kwamba kitabu kamili kiandikwe ambacho mahakimu na wengine wangekirejea, ili kupunguza mzigo wa mahakimu na kurahisisha kazi kwa wanaoshtakiana. Ibn al-Muqaffa’ aliandika barua kwa Khalifah al-Mansur kuhusu jambo hili, ambamo ilitajwa:

The Muslims generally used to perform Taqlīd to the mujtahidin despite their disagreements since the basis of their disagreements was the Sharī’ah evidence. So the understanding of every mujtahid of the address of the Legislator (khitab al-shaari’) is considered a Sharī’ah rule with respect to him and with respect to the one who makes Taqlīd to him. This is because because the address of the Legislator is the hukm shar’i (Sharī’ah rule) and the understanding of the Legislator’s address is a Sharī’ah rule but in respect to the one who understood it and in respect to the one who follows him in this understanding. Those who attained the understanding of the Legislator’s address used to perform Ijtihād. Those who did not reach the level of Ijtihād used to follow, in ahkām (rules), those who had reached the level of Ijtihād and practised Ijtihād. The issue was not that of following the faqih personally just as the issue is not one of making Taqlīd to a mazhab. Rather, the issue is about adopting the hukm shar’i deduced by the faqih and acting upon it. Since, the Muslim is ordered to follow the Sharī’ah rule only and act upon it and not follow a mazhab or person or act according to any particular mazhab or follow any particular person. When he is able to reach the hukm shar’i through his own Ijtihād he should do that, if not he should adopt a hukm deduced by someone else. In the early ages the mujtahidin could be counted by the thousands. That is why we find that the mujtahidin whom the Muslims used to follow were not restricted to four, five, six or any number of mazhabs, in fact there were many mazhabs and numerous mujtahidin. Each group used to follow rules deduced by a mujtahid whether he was from a mazhab or not. For example, the general population of Kufa acted upon the fatwa of Abu Hanifah and Sufyan al-Thawri but the Shi’a used to act upon the mazhab of Ja’far al-Sadiq. The practise of the people of Makkah used to be according to the fatwa of Ibn Jurayj and the people of Madina on the fatwas of Malik and the people of Basra on the fatwas of ‘Uthman and the people of al-Sham on the fatwas of al-Awza’i and the people of Egypt on the fatwas of Ibn Sa’d, and the people of Khurasan on the fatwas of ‘Abd Allah ibn al-Mubarak and some of the people of Yemen on the fatwas of Zayd ibn al-Husayn. Many of the Muslims used to follow the fatwas of Sa’id ibn al Musayyab, Ibn Abi Layla, ‘Ikrama, Rabi’i Ar-Ra’i, Muhammad ibn shihaab Az-Zuhri , Hasan Al Basari, Laith ibn sa’ad, Sufyan Ibn ‘Uyayna, Ishaq ibn Rahawiya, Abi Thawr, Dawud Az-Zahiri, Ibn shibrima and Ibn Jarir At-Tabari. Each of them was a Mujtahid and lead a mazhab. Each of the mazhabs from these mazhabs had a particular methodology in Ijtihād and a particular ra’i (opinion) in the ahkam. Many of the Mujtahidin and Imams were judges and rulers in the lands. The differences among the imams and the judges and rulers lead to a difference in the ahkam (rules), each one judged with his own opinion or according to the opinion of a faqih whose opinion he held. This resulted in the presence of different judgements in the state, due to this there were ‘Ulamā who were obviously inclined towards unifying the ruling by which judgement is given and wanted the Khalifah to issue an order for people to adhere to it. At that time, certain people who knew about the situation of the society took the view that a comprehensive book should be written to which judges and other should refer, so as to lighten the burden of the judges and make it easy for the litigants. Ibn al-Muqaffa’ wrote a letter to the Khalifah al-Mansur regarding this matter, in which it was mentioned:

Hata hivyo, al-Mansur hakutekeleza barua hii ingawa aliivutiwa nayo. Kwa hiyo alichukua hatua za kuwafanya Mafaqihi na wanahadithi waandike kile kilichowafikia, mpaka watu wawe na marejeo ambayo wangeweza kuyarejea. Sababu ya al-Mansur kutofuata maoni ya Ibn al-Muqaffa' katika kuweka katiba na kanuni za dola ambazo zingewaleta watu pamoja juu ya ahkaam maalum, ilikuwa yale yaliyotokea baina yake na Malik. Ibn Sa'ad anasimulia katika al-Tabaqat kwamba Malik bin Anas alisema:

However, al-Mansur did not act upon this letter although he was impressed by it. So he took steps to make the Fuqaha and the muhaddithin record what has reached them until people had references to which they could refer. The reason for al-Mansur not acting upon the opinion of Ibn al-Muqaffa’ in laying down a constitution and canons for the state which would have brought the people together on specific ahkāms was what transpired between him and Malik. Ibn Sa’ad narrates in al-Tabaqat that Malik bin Anas said:

Kwa sababu hiyo, madhhabu na maoni hayakuunganishwa, na ijtihadi pamoja na ra'y viliendelea kuwa kwa watu katika kuchukua hukmu waliyoona kuwa sahihi. Na uchaguzi ulibaki kwa mahakimu na watawala kuhukumu kwa kile walichoona kuwa kinafaa. Kutokana na hili, kila imamu wa fiqh alikuwa na wanafunzi waliokuja kusoma maoni yake na kueleza madhhabu yake, na mtazamo kuhusu tofauti hii iliyotokea ulibadilika, ikawa ni elimu inayojitegemea, wakaiita elimu ya khilafu ('ilm al-khilaf). Walisoma elimu hiyo kama walivyosoma usul al-fiqh. Walisema kuwa tofauti za maimamu ni rehema. Mwanafunzi wa kila imamu alikuwa akipanua matawi ya fiqh (furu'). Upanuzi huu ndio uliohifadhi madhhabu ya baadhi ya mujtahidina, na ndio sababu ya kutoweka kwa wengine. Al-Awza'i, al-Hasan al-Basri, al-Thawri na Ibn Jarir al-Tabari ni miongoni mwa maimamu wakubwa kwa upana wa elimu yao na ijtihadi yao. Hata hivyo, hawakupanua katika furu', bali walijizuia katika usul, na hawakuwa na wanafunzi wa kufafanua msimamo wa madhhabu yao; ndiyo maana hawakufuatwa na madhhabu yao hayakuenea. Kwa upande wa maimamu wengine kama Abu Hanifah, Ja'far al-Sadiq, Zayd bin al-Husayn, al-Shafi'i, Ahmad bin Hanbal na Malik, walikuwa na wanafunzi na wafuasi, hivyo madhhabu yao yalirekodiwa na kuendelea kuwepo. Licha ya vikwazo alivyoweka Abu Ja'far al-Mansur dhidi ya Ja'far al-Sadiq na wengine kutoka familia ya 'Ali, yeye alitoa hukumu na alikuwa na wanafunzi kutoka Shi'a na wengine. Walirekodi maoni yake na kuyaona kama kitu kinachofanana na Sunnah. Madhhabu yake yalienea katika maeneo mengi ya dunia. Abu Hanifah alikuwa na wanafunzi wengi, maarufu zaidi wakiwa ni Abu Yusuf, Muhammad bin al-Hasan al-Shaybani na Zufar. Wote walikuwa mujtahidina kama Abu Hanifah. Ingawa walichanganya maoni yao na yake, sifa inawaendea wao kwa kurekodi madhhabu ya Abu Hanifah. Vivyo hivyo kwa Imamu Malik. Aliishi Madina; alikuwa na wanafunzi wengi waliojulikana sana kwa kuchunguza kwa kina hadith na wapokezi wa hadith, hasa kuhusu kitabu al-Muwatta. Baada yake, wanafunzi wake walikuwa wakiandika fatwa zake, wakipanua mambo ya furu' na kutoa maoni yao kuhusu masuala mbalimbali. Licha ya umaarufu wa Malik, sifa ya kueneza mazhabu yake inawaendea wanafunzi wake. Kuhusu al-Shafi'i, yeye mwenyewe alijijengea umaarufu mkubwa katika usul al-fiqh, jambo linaloonyeshwa na kile kilichomo katika kazi kubwa ya al-Umm, ambayo pamoja na al-Risala na Ibtal al-Istihsan ni mifano mikuu ya mwamko wa kifikra wa zama zile. Wanafunzi wake, kama al-Rabi' na al-Muzni, walifuata mbinu hii, wakasoma maoni yake, wakapanua mazhabu yake, na hivyo ikaenea mbali na mbali. Vilevile kwa Ahmad ibn Hanbal, ingawa hadith ilitawala sana katika mazhabu yake, alikuwa na wanafunzi waliopanua mazhabu yake kwa ajili yake na kusoma maoni yake. Sifa kwanza kabisa inawaendea wanafunzi hao, si tu kwa kueneza mazhabu ya walimu wao na maimamu wao, bali pia kwa kufafanua fiqh na kuhakikisha inastawi hadi zama zao zikachukuliwa kuwa zenye mwangaza zaidi kuliko zama za maimamu. Kwani ilikuwa katika zama hizi ndipo zilipofanyika sharhi za ahkam na ufafanuzi wa dalili, na kwa njia hii mafaqihi walijitosa mbele katika kujifunza fiqh na kuifafanua, hasa elimu ya usul al-fiqh ambayo ndiyo msingi wa kweli wa fiqh. Hali ya fiqh iliendelea kuenea hadi ikastawi sana. Kilele cha kustawi kwake kilikuwa katika karne ya nne Hijria, karne moja baada ya kuundwa kwa mazhabu.