Sunan Abi Dawud, Hadith 4812 ⓘ
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.
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 " .
also referenced under: Hadith 4794 (Hasan) & Book 41, Hadith 4794 (USC-MSA)