It is narrated from Qays bin Abi Hazim that Umar (may Allah be pleased with him) gave the tribe of Bajilah a quarter of the Sawad (the cultivated land of Iraq), and they held it for some years. Then Jarir (may Allah be pleased with him) came as a delegate to Umar (may Allah be pleased with him), and he said: Were it not that I am a distributor who will be held accountable, you would have kept what was allotted to you; but I think that you should return it. So he returned it, and he rewarded him with eighty dinars.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 13043