Hizam bin Hisham bin Hubaysh al-Khuza'i heard his father say: I saw Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) with his waist tied firmly with a cord, while he was working with some of the sadaqah camels. Mansur said: As I remember, he was selling them by auction; whenever he sold a camel from them, he tied its cord around his waist, then he gave them away in charity, that is, those cords.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13118