Sahih al-Bukhari 2979

'Ubayd ibn Isma'il narrated to us; Abu Usama narrated to us from Hisham, who said: My father informed me, and Fatima also narrated to me from Asma' (may Allah be pleased with her), who said: I prepared the Messenger of Allah's travel provisions in Abu Bakr's house when he intended to migrate to Medina. We could find nothing with which to tie his food bundle and waterskin. I said to Abu Bakr, ‘By Allah, I can find nothing to tie them with except my waist belt.’ He said, ‘Cut it in two, and use one piece to tie the waterskin and the other to tie the food bundle.’ I did so, and for this reason she was called Dhat al-Nitaqayn, the woman of the two waist-belts.