Musnad Ahmad 38:12

Waki’ narrated to us, from Sufyan, from Salamah, from ‘Abdullah ibn ‘Abdur-Rahman ibn Abza, from his father: That the Prophet, peace and blessings of Allah be upon him, used to say when he reached the morning and when he reached the evening: "We have reached the morning upon the natural disposition (fitrah) of Islam, and upon the word of sincerity (Ikhlas), and upon the religion of our Prophet Muhammad, peace and blessings of Allah be upon him, and upon the creed of our father Ibrahim, inclining toward truth (Hanifan), a Muslim, and he was not of the polytheists."