It is narrated from some of the Muhajirun Companions (may Allah be pleased with them) that they said: "O Messenger of Allah (peace and blessings be upon him), we have never seen anyone (so self-sacrificing) like the people (that is, the Ansar) with whom we have stayed; they made us partners in their wealth and property and (taking the labour upon themselves) sufficed us in our needs of livelihood and burdens, so much so that we have come to fear that they may carry off the entire reward." The Prophet (peace and blessings be upon him) said: "It is not so; as long as you keep praying to Allah, the Mighty and Majestic, for them and keep mentioning them with goodness and praise (for their kindness), they will not take away all the reward alone."
Imam Abu Ya'la narrated this hadith in his Musnad; although its chain contains the link of al-Hasan al-Basri from some of the Muhajirun, this report is transmitted with an authentic chain from Sayyiduna Anas (may Allah be pleased with him) in other reliable sources such as Sunan al-Tirmidhi and Sunan Abi Dawud, in which the virtue of praying for and thanking the one who does a kindness is described.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 4140
Hadith Gradingمحدثین:إسناده ضعيف
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده ضعيف » «أخرجه سنن الترمذي برقم: 2487، وأخرجه مسند أحمد برقم: 12662، 12709، وأخرجه المستدرك على الصحيحين برقم: 2415، وأخرجه المعجم الأوسط للطبراني برقم: 7288، وأخرجه الأحاديث المختارة برقم: 1662، 1931، وأخرجه إتحاف الخيرة المهرة بزوائد المسانيد العشرة برقم: 2400، 5122، 6964»