صحيح البخاري

Narrated Anas:

When Um Sulaim gave birth to a child. she said to me, "O Anas! Watch this boy carefully and do not give him anything to eat or drink until you have taken him to the Prophet (ﷺ) tomorrow morning for the Tahnik." So the next morning I took the child to the Prophet (ﷺ) who was sitting in a garden and was wearing a Huraithiya Khamisa and was branding the she-camel on which he had come during the Conquest of Mecca.