Musannaf Ibn Abi Shayba 1:1616

Hussain bin Ali narrated to us, from Za’idah, from ‘Asim, from al-Musayyib. And someone other than Hussain said: From Za’idah, from al-Musayyib, from Siwar, from Hafsah, who said: The right hand of the Messenger of Allah, may Allah bless him and grant him peace, was for his food, his drink, his purification, his clothing, and his prayer. And his left hand was for what was other than that.