The Messenger of Allah (may Allah's peace and blessings be upon him) forbade riding the camel that feeds on dung as well as drinking its milk
Authentic hadithعن ابن عمر رضي الله عنهما ، قال: "نهى رسول الله صلى الله عليه وسلم عن الجَلَّالَة في الإبِل: أنْ يُرْكَبَ عليها، أو يُشْرَب مِن أَلْبَانِها".
Ibn ‘Umar (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) forbade riding the camel which feeds on dung as well as drinking its milk.
Explanation
This Hadīth illustrates forbiddance of riding a camel or any other animal that feeds on dung, dirt, and filth or drinking its milk. The reason is that the flesh and milk of such animals is nurtured with filth, so they are not pure. However, if they are given fodder for three or more days, their meat and milk become lawful for consumption.
Source · Narrated by Ibn Majah - Narrated by At-Termedhy - Narrated by Abu Daoud
From the Hadith Encyclopedia (hadeethenc.com).