Muwatta Malik, Book 21, Hadith 998 (In-Book)

Yahya related to me from Malik from Yahya ibn Said that Umar ibn al-Khattab in one year gave 40,000 camels as mounts. Sometimes he would give one man a camel to himself. Sometimes he would give one camel between two men to take them to Iraq. A man from Iraq came to him and said, "Give Suhaym and I a mount.''Umar ibn al-Khattab said to him,"l demand from you, by Allah!, is Suhaym a water skin?" He said, "Yes."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ عُمَرَ بْنَ الْخَطَّابِ، كَانَ يَحْمِلُ فِي الْعَامِ الْوَاحِدِ عَلَى أَرْبَعِينَ أَلْفِ بَعِيرٍ يَحْمِلُ الرَّجُلَ إِلَى الشَّامِ عَلَى بَعِيرٍ وَيَحْمِلُ الرَّجُلَيْنِ إِلَى الْعِرَاقِ عَلَى بَعِيرٍ فَجَاءَهُ رَجُلٌ مِنْ أَهْلِ الْعِرَاقِ فَقَالَ احْمِلْنِي وَسُحَيْمًا ‏.‏ فَقَالَ لَهُ عُمَرُ بْنُ الْخَطَّابِ نَشَدْتُكَ اللَّهَ أَسُحَيْمٌ زِقٌّ قَالَ لَهُ نَعَمْ ‏.‏

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also referenced under: Book 21, Hadith 38 (USC-MSA)