Maliks Muwatta Book 2, Hadith Number 81.

Section : The Repetition of the Prayer by a Person in a State of Major Ritual Impurity, his Doing Ghusl, when He has Prayed without Remembering it, and his Washing his Garments.

Yahya related to me from Malik from Ismail ibn Abi Hakim that Ata ibn Yasar told him that the Messenger of Allah, may Allah bless him and grant him peace, said the takbir in one of the prayers and then indicated to them with his hand to stay in place. He left and then returned with traces of water on his skin.