He adds...

He adds: Concerning classification of hadith into sections by the compilers, it is more proper for permission, or rather negating dispute in it is excluded. This practice was continuously followed by most of the memorizers among ‘ulama’ and traditionists (muhaddithun), and others among classes of scholars. Muslim was among those permitting abridgement of hadith, referring to this fact in his introduction.

Abu Shamah, in his book Mukhtasar Kitab al-Mu’ammal, 172 is reported to have said: ‘That which is usually practised by pundits of fiqh in relation to the Prophetic traditions and narrated reports, being their abundant inferences from the weak (unauthentic) traditions to confirm their claims, and support their sayings, deleting some of the hadith words once, and adding to them another time. There are numerous examples for this practice in the books of Abu al-Ma’ali and his companion Abu Hamid.