Musannaf Ibn Abi Shayba 28:1056

Narrated to us Abd al-Wahhab al-Thaqafi, from Humayd, from Anas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) had a she-camel called al-Adba’, and she would not be outrun. Then a Bedouin came on a young camel of his and outran her. This distressed the Muslims. When the Messenger of Allah (peace and blessings of Allah be upon him) saw what was on their faces, they said: "O Messenger of Allah, al-Adba’ has been outrun." The Messenger of Allah (peace and blessings of Allah be upon him) said: "It is a right upon Allah that He does not raise anything in this world except that He lowers it."