Sahih Muslim 1603
Sahih Muslim · Book 22: The Book of Musaqah · Pawning (Rahn) and its permissibility whether one is travelling or not
حَدَّثَنَاهُ أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا حَفْصُ بْنُ غِيَاثٍ ، عَنِ الأَعْمَشِ ، عَنْ إِبْرَاهِيمَ ، قَالَ حَدَّثَنِي الأَسْوَدُ ، عَنْ عَائِشَةَ ، عَنِ النَّبِيِّ صلى الله عليه وسلم مِثْلَهُ . وَلَمْ يَذْكُرْ مِنْ حَدِيدٍ .
This hadith has been narrated on the authority of 'A'isha (Allah be pleased with her), through another chain ol transmitters, but no mention was made of (its being made) of iron.