Sayyiduna Safinah (may Allah be pleased with him) said: I was with the Messenger of Allah (peace and blessings be upon him) on a journey, and whoever of his (peace and blessings be upon him) companions found his baggage heavy would load it onto me, until I was carrying a great deal. Then the Prophet (peace and blessings be upon him) passed by me and said: "You are nothing but a ship."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6411