Hazrat Abdullah Mughaffal (Radiallahu anhu) reports, "Sayyidina Rasulullah (Sallallahu alaihe wasallam) prohibited the combing of hair, but allowed it to be done occasionally." (RU)
English reference (RU): Book 4, Hadith 34 (RU)
Arabic reference (RU): Book 4, Hadith 35 (RU)