Musnad Ahmad 511:2

Ya'la ibn 'Ubayd narrated to us, Isma'il narrated to us, from Qays, from Dukayn ibn Sa'id al-Muzani, who said: We came to the Messenger of Allah, may Allah bless him and grant him peace, as four hundred and forty riders, asking him for food. He said to 'Umar: "Go and give them." 'Umar said: "O Messenger of Allah, there remain only a few sa's of dates; I do not see that they will suffice me for the summer." He said: "Go and give them." 'Umar said: "I hear and I obey." He said: So 'Umar took the key from his waist-wrapper and opened the door, and there was something like a crouching young camel made of dates. He said to us: "Take." Every man among us took what he liked. Then I turned back, and I was among the last of the people, and it was as if we had not diminished the dates by a single one.