Musannaf Ibn Abi Shaybah

Hazrat Sahl bin Sa’d narrates that two men disagreed about which mosque was meant by the phrase “the mosque founded on piety.” One said it referred to the Prophet’s Mosque, and the other said it referred to the Quba Mosque. Both of them came to the service of the Prophet (peace and blessings be upon him), and he said, “It refers to my mosque.”