Musnad Ahmad 32:646

Yahya ibn Ghaylan narrated to us, Rashdin narrated to us, he said: Amr ibn al-Harith narrated to me, from Bukayr, from al-Dahhak al-Qurashi, from Anas ibn Malik, who said: I saw the Messenger of Allah, peace and blessings of Allah be upon him, during a journey, praying the Duha prayer [consisting of] eight rak'ahs. When he finished, he said: "I prayed a prayer of desire and fear. I asked my Lord, the Almighty and Majestic, for three things; He granted me two and withheld one from me. I asked Him not to afflict my nation with years [of famine], and not to let their enemy prevail over them, and He did so. And I asked Him not to clothe them in sects [causing them to be divided], but He refused me."