When the mentioned reasons were removed, prohibition was cancelled, permission was given, and the action was done. As for the prohibition or undesirability of writing down the Sunnah which was done by some Companions and Followers, it can be interpreted as follows:
A- The fear that another book will be written and be like the Qur'an.
B- A writer may depend on his writing and abandon memorization, thus the talent of memorization shall be weakened.
C- The fear that these books would fall in the hands of those who do not understand them, leading them to straying and destruction.
The narration of Abu Nadrah on the authority of Abu Sa`id Al Khudry that was mentioned previously bearing this meaning (which is the fifth narration in the Hadiths of prohibition).
As for the second explanation, it was said by Masruq to `Alqamah when he said: (Write for me similar issues. He said: Have not you known that writing is undesirable? He said: Yes. However, I want to memorize them then burn them. He said: There is no harm in doing so). (1)
As for the third explanation, it was said by `Ubaydah when it was reported from him that he called someone to bring his books to erase them at his death. When people asked about that, he said: I fear that some people would understand it differently. (2)
Second, writing the Sunnah was a reality in the generation of the venerable Companions (may Allah be pleased with them), where reliable resources according to the scholars of Hadith proved the possession of the Companions (may Allah be pleased with them) to Hadiths, papers, and copies that they wrote for themselves or were written to them according to their will or were found at them, of which:
1- The copy of Abu Bakr As-Siddiq (may Allah be pleased with him) which contained the channels in which Zakah is paid. (3)
2- The copy of `Umar ibn Al Khattab (may Allah be pleased with him) which contained the charities of the Prophet (peace be upon him). (4)
3- The sincere paper of `Ali ibn Abu Talib (may Allah be pleased with him). (5)
4- The book of Judgment of `Ali (6) which was written down by `Abdullah ibn `Abbas (may Allah be pleased with him) and Ibn `Abbas had also a paper on Tafsir. (7)
5- The paper of Fatimah Az-Zahra' (may Allah be pleased with her) which contained some Hadiths. (8)
6- The books of Sa`d ibn `Ubadah Al Ansary (may Allah be pleased with him). (9)
7- A copy of Tafsir attributed to Uby ibn Ka`b (may Allah be pleased with him). (10)
8- The book of `Abdullah ibn Mas`ud (may Allah be pleased with him). (11)
9- The book of the prescribed shares of inheritance of Zayd ibn Thabit Al Ansary (may Allah be pleased with him). (12)
10- The paper of Samurah ibn Jundub (may Allah be pleased with him). (13)
11- The sincere paper of `Abdullah ibn `Amr ibn Al `As (may Allah be pleased with him). (14)
12- The book of Al Mughirah ibn Shu`bah which he dictated to Warid the scribe of Mu`awiyah. (15)
13- The Hadiths of Anas ibn Malik which he wrote from the Messenger of Allah (peace be upon him) which he used to dictate to his students. (16)
These papers and books, which were written down in that early age, were the early work of writing about the Sunnah which if they were lost in the middle of major books because of various narrators and writing, they were the cornerstone of collecting and writing the Sunnah. (17)
(1) See: Taqyid Al `Ilm, p. 58 59 and Jami` Bayan Al `Ilm 1 / 80.
(2) Reported by Ad-Darimy in the introduction, chapter on scholars who do not adopt the view of writing Hadith 1 / 121, Al Khatib in Taqyid Al `Ilm p. 61, and Ibn `Abdul-Bar in Jami` Bayan Al `Ilm 1 / 80.
(3) Reported by Al Bukhari in his Sahih in the book of Zakah, chapter on Zakah on properties (3 / 312), chapter on "it is not proper to combine two different matters," (3 / 314) chapter on things which are of two mixtures, (3 / 315) chapter on a person who has the fixed amount of Zakah who would pay Bint Makhad (a one-year-old she-camel) (3 / 316) the chapter on Zakah of sheep (3 / 317), Al Hakim in Al Mustadrak in the book of Zakah, chapter on a person who gives a charity out of ill-gotten money (1 / 390), and Abu Dawud in his Sunan in the book of Zakah, chapter on Zakat As-Sa'imah (animals that graze on natural grass without the interference of man) (2 / 214). However, the book of charity which was attributed to Abu Bakr (may Allah be pleased with him) is the book of charity which was written by the command of the Messenger of Allah (peace be upon him). You may revise that in: Sunan Ad-Darimy in the book of Zakah, chapter on the Zakah of camels (1 / 382) from Ibn `Umar, but what is important is that he had a copy of it.
(4) Al Amwal of Abu `Ubayd p. 370, which Nafi` reviewed to Ibn `Umar several times.
(5) Reported by Al Bukhari in the book of knowledge, (1 / 204) and Muslim in the book of Hajj, chapter on the virtue of Al Madinah (Medina) (2 / 995).
(6) Sahih Muslim in the introduction, chapter on reported from non-trustworthy narrators (1 / 13), At-Tabaqat Al Kubra of Ibn Sa`d (5 / 216) and Ibn Sa`d said: He had books as amount as a donkey can carry.
(7) Taqyid Al `Ilm p. 91, 92 and Muftah As-Sa`adah 2 / 64 - 65.
(8) Musnad Imam Ahmad (6 / 283) and Makarim Al Akhlaq of Al Khara'ity p. 37.
(9) Musnad Imam Ahmad (5 / 285).
(10) Muftah As-Sa`adah (2 / 69) and said: He had a big copy which was narrated by Abu Ja`far Al Razy from Al Rabi` Ibn Anas from Abu Al `Aliyah from him; this is an authentic chain of narration. See: Kashf Al Litham 1 / 113.
(11) Jami` Bayan Al `Ilm wa Fadluh 1 / 42.
(12) Reported by Al Bukhari in the book of Adhan (call to Prayer), chapter on Dhikr (remembrance of Allah) after Salah (2 / 325) and the book of invocations, chapter on invocation after Salah 11 / 133.
(13) See his paper in Al Isti`ab (2 / 653) Tahdhib At-Tahdhib (4 / 236), and Al A`lam (3 / 204).
(14) Reported by Ad-Darimy in the introduction, chapter on scholars who gave concessions in writing down knowledge (1 / 127), Ibn Sa`d in At-Tabaqat (2 / 373)
(4 / 262) (7 / 494), and Al-Ramahurmuzy in Al Muhaddith Al Fasil p. 367.
(15) See: Usd Al Ghabah 3 / 117, Al Isabah 4 / 236, and Kitab Al `Ilm of Abu Khaythamah p. 117.
(16) Tarikh Baghdad 8 / 258.
(17) See: Kashf Al Litham 1 / 117 - 118.