Musnad Ahmad 1016:9

'Abd al-Razzaq narrated to us, Ma'mar informed us, from Yahya ibn Abi Kathir, from Muhammad ibn 'Abd al-Rahman ibn Thawban, from 'Abdullah ibn Malik ibn Buhaynah, that the Prophet, peace and blessings of Allah be upon him, passed by him while he was praying, lengthening his prayer—or something similar—before the dawn prayer. The Prophet, peace and blessings of Allah be upon him, said to him: "Do not make this like the noon prayer, before it and after it; place a separation between them."