Musannaf Ibn Abi Shayba 28:505

33033. Abdullah ibn al-Mubarak narrated to us, from Ma'mar, from Yahya ibn Qays al-Ma'aribi, from a man, from Abyad ibn Hammal, that he requested the Prophet, may Allah bless him and grant him peace, to grant him the salt [mine] that is in Ma'rib. He intended to grant it to him, but a man said to the Messenger of Allah, may Allah bless him and grant him peace, "It is like flowing water." So he refused to grant it to him.