Sunan Abi Dawud, Book 2, Hadith 639 (USC-MSA) ⓘ
Zaid b. Qunfudh said that his mother asked Umm Salamah : In how many clothes should a woman pray? She replied; she would pray wearing a veil and a long shirt which covers the surface of her feet.
حَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ مُحَمَّدِ بْنِ زَيْدِ بْنِ قُنْفُذٍ، عَنْ أُمِّهِ، أَنَّهَا سَأَلَتْ أُمَّ سَلَمَةَ مَاذَا تُصَلِّي فِيهِ الْمَرْأَةُ مِنَ الثِّيَابِ فَقَالَتْ تُصَلِّي فِي الْخِمَارِ وَالدِّرْعِ السَّابِغِ الَّذِي يُغَيِّبُ ظُهُورَ قَدَمَيْهَا .
also referenced under: Hadith 639 (DarusSalam) & Hadith 639 (Hasan)