Qays bin Abi Hazim said: We were a quarter of the people on the day of al-Qadisiyyah, and Sayyiduna Umar (may Allah be pleased with him) gave us a quarter of the Sawad; we collected its kharaj for three years. After that, the delegation of Jarir bin Abdullah (may Allah be pleased with him) came to Sayyiduna Umar (may Allah be pleased with him), and he said: Were I not afraid of being questioned about the distribution, I would have kept you upon that allotment; but in my view you should return it to the Muslims. They did so, and Sayyiduna Umar (may Allah be pleased with him) rewarded him with eighty dinars.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18378