Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 704
Narrated Ibn Umar:
Allah's Apostle said to his companions who were at Al-Hijr, "Do not enter upon these people who are being punished, except in a weeping state, lest the same calamity as of theirs should befall you..."