It is narrated from Ikrimah (may Allah have mercy on him) that Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: Sayyiduna Ali (may Allah be pleased with him) made Fatimah (may Allah be pleased with her) lawful for himself with nothing but a coat of iron mail.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14349