Sahih al-Bukhari 2982

Narrated Salama:Once the journey-food of the people ran short and they were in great need. So, they came to the Prophet to take his permission for slaughtering their camels, and he permitted them. Then `Umar met them and they informed him about it. He said, "What will sustain you after your camels (are finished)?" Then `Umar went to the Prophet (ﷺ) and said, "O Allah's Messenger (ﷺ)! What will sustain them after their camels (are finished)?" Allah's Messenger (ﷺ) said, "Make an announcement amongst the people that they should bring all their remaining food (to me)." (They brought it and) the Prophet (ﷺ) invoked Allah and asked for His Blessings for it. Then he asked them to bring their food utensils and the people started filling their food utensils with their hands till they were satisfied. Allah's Messenger (ﷺ) then said, "I testify that None has the right to be worshipped but Allah, and I am His Apostle. "