Maliks Muwatta Book 9, Hadith Number 49.

Section : Placing One Hand on the Other in the Prayer.

Yahya related to me from Malik that Abd al-Karim ibn Abi’l-Mukhariq al-Basri said, “Among things the Prophet, may Allah bless him and grant him peace, said and did are| ‘As long as you do not feel ashamed, do whatever you wish’, the placing of one hand on the other in prayer (one places the right hand on the left), being quick to break the fast, and delaying the meal before dawn.”