Yahya related to me from Malik from Abu Bakr ibn Nafi from hisfather Nafi from Abdullah ibn Umar that the Messenger of Allah, mayAllah bless him and grant him peace, ordered the moustache to betrimmed and the beard to be left.
USC-MSA web (English) reference: Book 51, Hadith 1
Arabic reference: Book 51, Hadith 1733