Riyad as-SalihinChapter 17Hadith 1019
Full Sharh — Riyad as-Salihin 1019
وعن بريدة رضي الله عنه أن رجلا نشد في المسجد فقال: من دعا إلى الجمل الأحمر، فقال رسول الله صلى الله عليه وسلم : "لا وجدت، إنما بنيت المساجد لم بنيت له" ((رواه مسلم)).
English Translation
Buraidah (May Allah be pleased with him) said:: 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.).".
Source
Riyad as-Salihin(رياض الصالحين)
The Book of the Prohibited actions
Hadith Number
1019