Musnad Abu Ya'la al-Mawsili 247:14

Abu Bakr narrated to us, Ahmad bin Abdullah narrated to us, from Umm al-Aswad, from Munyah, from the hadith of Abu Barzah, who said: They asked the Messenger of Allah, peace and blessings of Allah be upon him, about an uncircumcised man: "May he perform Hajj to the House of Allah?" He said: "No, Allah the Mighty and Majestic has forbidden me from that until he is circumcised."