Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "If you sell fruit to your brother and it is struck by a calamity, then it is not lawful for you to take anything from him. How would you take your brother's wealth without right?"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10631