Sayyiduna Abu Sa'id (may Allah be pleased with him) said: We were with the Prophet (peace and blessings be upon him) on a journey when suddenly a man came riding a camel, turning it to the right and to the left. The Prophet (peace and blessings be upon him) said: "Whoever has a spare mount should give it to the one who has no mount, and whoever has surplus provisions should give them to the one who has none." In this way he mentioned various kinds of wealth, until we thought that we had no right at all to any surplus wealth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19666