It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) reached Khaybar at night. When morning came, he mounted, and his Companions also mounted and set off. The people of Khaybar came out with their tools and baskets as usual, and when they saw the Prophet (peace and blessings be upon him), they cried out: By Allah! Muhammad and his army are advancing! Then they fled in fear, and the Messenger of Allah (peace and blessings be upon him) said: "Khaybar is ruined! When we descend upon the courtyard of a people, evil is the morning of those who were warned."
Sayyiduna Anas (may Allah be pleased with him) said: That day I was riding behind Sayyiduna Abu Talhah (may Allah be pleased with him) on the same mount, and my knee was touching the knee of the Messenger of Allah (peace and blessings be upon him). In another narration it says: My foot was touching the foot of the Messenger of Allah (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3240