Volume 4, Book 56, Number 840:
Narrated Anas bin Malik:
Allah’s Apostle reached Khaibar in the early morning and the people of Khaibar came out with
their spades, and when they saw the Prophet they said, “Muhammad and his army!” and returned
hurriedly to take refuge in the fort. The Prophet raised his hands and said, “Allah is Greater! Khaibar
is ruined ! If we approach a nation, then miserable is the morning of those who are warned.”