It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Muhajirun said: O Messenger of Allah! The Ansar have taken all the reward. The Prophet (peace and blessings of Allah be upon him) said: "That is not so, as long as you pray for them and mention them with words of praise."
Hadith Referenceالادب المفرد / كتاب / 217
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه أبوداؤد ، كتاب الأدب ، باب فى شكر المعروف : 4812 و الترمذي : 2487 - صحيح الترغيب : 977 و صححه الحاكم على شرط مسلم : 63/2 ، و وافقه الذهبي»