(96) باب الرَّجُلِ يَبِيعُ السِّلْعَةَ فَيَسْتَحِقُّهَا مُسْتَحِقٌّ
It was narrated from Sammurah that the Messenger of Allah said:
"If a woman is married off by two guardians, then the first marriage is the one that counts, and if a man sells something to two men, it belongs to the first one."
Reference: Sunan an-Nasa'i 4682
In-book reference: Book 44, Hadith 234
English translation: Vol. 5, Book 44, Hadith 4686