حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا حَمَّادٌ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، أَنَّ الْمُهَاجِرِينَ، قَالُوا يَا رَسُولَ اللَّهِ ذَهَبَتِ الأَنْصَارُ بِالأَجْرِ كُلِّهِ . قَالَ لاَ مَا دَعَوْتُمُ اللَّهَ لَهُمْ وَأَثْنَيْتُمْ عَلَيْهِمْ "
Narrated Anas ibn Malik:
The Immigrants (Muhajirun) said: Messenger of Allah! the Helpers (Ansar) got the entire reward. He said: no, so long as you pray to Allah for them and praise them.
Reference: Sunan Abi Dawud 4812
In-book : Book 43, Hadith 40
English translation : Book 42, Hadith 4794