حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا شُعْبَةُ، عَنْ عَاصِمِ بْنِ عُبَيْدِ اللَّهِ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِيهِ، عَنْ عُمَرَ، - رضى الله عنه - قَالَ اسْتَأْذَنْتُ النَّبِيَّ صلى الله عليه وسلم فِي الْعُمْرَةِ فَأَذِنَ لِي وَقَالَ ‏"‏ لاَ تَنْسَنَا يَا أُخَىَّ مِنْ دُعَائِكَ ‏"‏ ‏.‏ فَقَالَ كَلِمَةً مَا يَسُرُّنِي أَنَّ لِي بِهَا الدُّنْيَا قَالَ شُعْبَةُ ثُمَّ لَقِيتُ عَاصِمًا بَعْدُ بِالْمَدِينَةِ فَحَدَّثَنِيهِ وَقَالَ ‏"‏ أَشْرِكْنَا يَا أُخَىَّ فِي دُعَائِكَ ‏"‏ ‏.‏

Narrated Umar ibn al-Khattab: I sought permission of the Prophet (PBUH) to perform umrah. He gave me permission and said: My younger brother, do not forget me in your supplication. He (Umar) said: He told me a word that pleased me so much so that I would not have been pleased if I were given the whole world. The narrator Shu'bah said: I then met Asim at Medina. He narrated to me this tradition and reported the wordings: "My younger brother, share me in your supplication." Translation Not Available

Book Ref: Sunan Abi Dawud Book 8 Hadith 1498
Web Ref:  Sunan Abi Dawud Book 8 Hadith 1493