وَعَنْ هِشَامِ بْنِ زَيْدٍ عَنْ أَنَسٍ
قَالَ: دَخَلْتُ عَلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهُوَ فِي مِرْبَدٍ فَرَأَيْتُهُ يَسِمُ شَاءَ حسبته قَالَ: فِي آذانها
Hisham ibn Zaid quoted Anas as saying that he went to visit the Prophet (sallallahu alayhi wa sallam) when he was in an enclosure and saw him branding sheep. He thought he said it was on their ears.
Mishkat al-Masabih 3916, Book 21, Game and Animals Which May Be Slaughtered, Hadith 17. 1 min read