Sayyiduna Abu al-Tufayl (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "I saw in a dream as though I was drawing water from the ground, and black sheep and greyish sheep came to me. Then Abu Bakr came and drew one or two buckets, and there was weakness in his drawing; may Allah Almighty forgive him. Then Umar came and began to draw water, and the bucket turned into a large bucket. He filled the cistern and quenched the thirst of those who came. I have not seen such a powerful man who drew water better than Umar. I interpreted it to mean that the black sheep are the Arabs and the greyish sheep are the non-Arabs."
Ahmad recorded it; its chain contains Ali bin Yazid, in whom there is weakness, and the rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الخلافة / 8927