Muwatta Imam Malik Book of Zakat, Hadith 48

Yahya related to me from Malik from Ibn Shihab that as-Sa'ib ibn Yazid said, "As a young man I used to work with Abdullah ibn Utba ibn Masud in the market of Madina in the time of Umar ibn al-Khattab and we used to take a tenth from the Nabateans."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنِ السَّائِبِ بْنِ يَزِيدَ، أَنَّهُ قَالَ كُنْتُ غُلاَمًا عَامِلاً مَعَ عَبْدِ اللَّهِ بْنِ عُتْبَةَ بْنِ مَسْعُودٍ عَلَى سُوقِ الْمَدِينَةِ فِي زَمَانِ عُمَرَ بْنِ الْخَطَّابِ فَكُنَّا نَأْخُذُ مِنَ النَّبَطِ الْعُشْرَ .