Hadith 8:2314
Abu Bakr narrated to us, he said: Yahya bin Sa'id narrated to us, from Ibn Jurayj, from Abu al-Zubayr, that he heard Jabir bin Abdullah saying—with the pads of his fingers—regarding the Muhrim (a person in the state of Ihram) scratching his head. He said: And someone informed me who saw Umar scratching [his head] vigorously.
حدثنا أبو بكر قال حدثنا يحيى بن سعيد عن بن جريج عن أبي الزبير أنه سمع جابر بن عبد الله يقول ببطن أنامله يقول في حك المحرم رأسه قال وأخبرني من رأى عمر يحك حكا