Sayyiduna Yazid bin Ma'bad (may Allah be pleased with him) said: I came to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) asked me about al-Yamamah: "Which tribe has the greatest number among its inhabitants?" I wanted to name Banu Abdullah bin al-Du'il, but then I disliked lying to the Prophet of Allah, so I said: "The greatest number of them is among Banu Ubayd." He (peace and blessings be upon him) said: "You have spoken the truth. It is a land that has grown up in hardship, and its people will never perish." The people said: "O Messenger of Allah, why is that?" He (peace and blessings be upon him) said: "Because they work with their own hands and eat together with their slaves."
Hadith Referenceالمعجم الكبير للطبراني / باب الياء / 18860