After stating that whatever the Prophet left of traditions...

After stating that whatever the Prophet left of traditions and sayings were neither written nor classified in the reference books during the era of his and eminent Followers, since they forbade from this practice, as recorded in Sahih Muslim, Ibn Hajar says in his introduction to Fath al-Bari: "The writing of traditions and classification of reports (akhbar) took place in the last days of the era of Tabi'un, when the ulama’; spread abroad through the metropolises and innovation multiplied by the Kharijites and Rafidites...

etc." Al-Bukhari and al-Tirmidhi reported from Abu Hurayrah that he said: "None among the Prophet's was more prolific in narrating the hadith than me except Abd Allah ibn 'Amr, as he used to write (the hadith)…