Musnad Ahmad 33:174

'Abd al-Rahman narrated to us, from Malik, from Wahb ibn Kaysan, from Jabir ibn 'Abd Allah, who informed him: "The Messenger of Allah (peace and blessings of Allah be upon him) sent out a military detachment of three hundred men and appointed Abu 'Ubaydah ibn al-Jarrah as their commander. Our provisions ran out, so Abu 'Ubaydah gathered what remained of their provisions and placed them in a bag. He would ration it for us until each of us would receive one date every day." A man said to him, "O Abu 'Abd Allah, what benefit did a single date provide you?" He replied, "We felt its loss when it was gone." "We continued until we reached the seashore, where we found a whale like a great mound. The army ate from it for eighteen nights. Then, Abu 'Ubaydah took two of its ribs and set them up, then he ordered a riding camel to be saddled, and it passed underneath them without touching them."