Hisham bin Zayd reported,

He narrated that when his mother gave birth, they took the child to the Prophet ﷺ for him to perform tahnik. He said, I found the Prophet ﷺ in a livestock enclosure branding sheep.Shuba said, To the best of my knowledge, he said, on their ears.

Muslim 5555

Sahih

حدثنا محمد بن المثنى حدثنا محمد بن جعفر حدثنا شعبة

عن هشام بن زيد قال سمعت أنسا

يحدث أن أمه حين ولدت انطلقوا بالصبي إلى النبي ﷺ يحنكه قال فإذا النبي ﷺ في مربد يسم غنما قال شعبة وأكثر علمي أنه قال في آذانها

مسلم 5555صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Clothing and adornment
Chapter
Permissibility of branding non-human animals on other than the face and its recommendation for zakat and jizya livestock
Numbering
Darussalam 5555
Muslim 5555