Abu Dawud Book 4, Hadith Number 1789.

Narated By Sa’id ibn al-Musayyab : A man from the Companions of the Prophet (PBUH) came to Umar ibn al-Khattab (may Allah be pleased with him). He bore witness before him that when he (the Prophet) was suffering from a disease of which he died he heard the Apostle of Allah (PBUH) prohibiting performing of umrah before hajj.