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."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ عَبْدِ الْكَرِيمِ بْنِ أَبِي الْمُخَارِقِ الْبَصْرِيِّ، أَنَّهُ قَالَ مِنْ كَلاَمِ النُّبُوَّةِ إِذَا لَمْ تَسْتَحِي فَافْعَلْ مَا شِئْتَ وَوَضْعُ الْيَدَيْنِ إِحْدَاهُمَا عَلَى الأُخْرَى فِي الصَّلاَةِ يَضَعُ الْيُمْنَى عَلَى الْيُسْرَى وَتَعْجِيلُ الْفِطْرِ وَالاِسْتِينَاءُ بِالسَّحُورِ ‏.‏
USC-MSA web (English) reference : Book 9, Hadith 49
Arabic reference : Book 9, Hadith 380