Riyad us Saliheen: Hadith 1697

A man announced (the loss of his camel) in the mosque, uttering these words: "Has any one seen my red camel?" Upon this the Messenger of Allah (ﷺ) said, "May it not be restored to you! The mosques are built for what they are meant to be (i.e., prayer, remembrance of Allah, acquiring knowledge, etc.)."

[Muslim].