وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ صَدَقَةَ بْنِ يَسَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ قَالَ وَاللَّهِ لأَنْ أَعْتَمِرَ قَبْلَ الْحَجِّ وَأُهْدِيَ أَحَبُّ إِلَىَّ مِنْ أَنْ أَعْتَمِرَ بَعْدَ الْحَجِّ فِي ذِي الْحِجَّةِ ‏.‏

Yahya related to me from Malik, from Sadaqa ibn Yasar, thatAbdullah ibn Umar said, "By Allah, I would rather do umra before hajjand sacrifice an animal than do umra after hajj in the month ofDhu'l-Hijja." Translation Not Available

Book Ref: Muwatta Imam Malik Book 20 Hadith 767
Web Ref:  Muwatta Imam Malik Book 20 Hadith 62