Musnad Ahmad 27:893

Ya'mar ibn Bishr narrated to us, Abdullah informed us, Ma'mar informed us, from al-Zuhri, Salim ibn Abdullah informed me, from his father, that the Prophet, peace and blessings of Allah be upon him, when he passed by al-Hijr, said: "Do not enter the dwellings of those who wronged themselves, unless you are weeping, lest what befell them befall you." And he covered his head with his garment while he was upon his mount.