The Book of Water
2/10. Chapter:
Concession With Regard To The Leftovers Of A Women (After Purification)
Sunan an-Nasai
أَخْبَرَنَا هَارُونُ بْنُ عَبْدِ اللَّهِ، قَالَ حَدَّثَنَا مَعْنٌ، قَالَ حَدَّثَنَا مَالِكٌ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ الرِّجَالُ وَالنِّسَاءُ يَتَوَضَّئُونَ فِي زَمَانِ رَسُولِ اللَّهِ صلى الله عليه وسلم جَمِيعًا .
It was narrated that Ibn 'Umar said: "Men and women used to perform Wudu' together during the time of the Messenger of Allah (ﷺ)."
Reference : Sunan an-Nasa'i 342In-book reference : Book 2, Hadith 18English translation : Vol. 1, Book 2, Hadith 343