مُوَطَّأُ مَالِكٍ
Muwatta Malik 722
Hajj
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ يَقُولُ مَا فَوْقَ الذَّقَنِ مِنَ الرَّأْسِ فَلاَ يُخَمِّرْهُ الْمُحْرِمُ .
Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to say that a man in ihram should not veil anything above his chin .
Arabic/English book reference: Book 20, Hadith 13