I went early to the Messenger of Allah ﷺ carrying Abdullah, the son of Abu Talha, so he could perform tahnik for him. I found him with a branding iron in his hand, marking the camels of charity.
غدوت إلى رسول الله ﷺ بعبد الله ابن أبي طلحة يحنكه، فوافيته في يده الميسم يسم إبل الصدقة.
Bukhari narrated it in the chapter on zakat (1502), and Muslim in the chapter on clothing (2119: 112), both through Walid bin Muslim, who said, Abu Amr Uzai narrated to us, who said, Ishaq bin Abdullah bin Abu Talha narrated to me, from Anas, and he related it.Wasm comes from wasama, yasimu, wasmatan, meaning to mark something by branding it. Al-mimsam is the iron instrument used for branding.