Chapter 35: Combing the Hair (Kitab Al-Tarajjul)
Sa' id b. Jubair said: There is no harm in fastening the hair with silk or woollen threads. Abu Dawud said: It appears that he held the view that what is prohibited is the adding of the hair of women. Abu Dawud said: Ahmad (b. hanbal) used to say: There is no harm in tying the hair with silk or woollen threads.
Sunan Abi Dawud 4171