Musannaf Ibn Abi Shayba 3:1754

Abu Bakr narrated to us, he said: Yazid ibn Harun narrated to us, he said: Husayn al-Mu'allim informed us, from Budayl, from Abu al-Jawza', from 'Aisha, that the Prophet, peace and blessings of Allah be upon him, used to begin the prayer with the takbir and the recitation with "Al-hamdu lillahi rabbil-'alamin."