Sahih Muslim Book 24, Hadith Number 5285.

Chapter : It is forbidden to beat the animal on the face or cauterise at the face.

Anas reported that Umm Sulaim gave birth to a child. She said to him: Anas, see that nothing is given to this child until he is brought to Allah’s Apostle (may peace be upon him) in the morning, so that he should chew some dates and touch his palate with it. I went to him in the morning and he was in the garden at that time having the mantle of Jauniyya over him and he was bus in cauterising (the camels) which had been brought to him (as spoils of war) in victory (over the enemy).