Musnad Ahmad 656:2

Abu Sa’id narrated to us, Za’idah narrated to us, Mansur narrated to us, from Ibrahim, from ‘Alqama and al-Aswad, who said: A group of people came to ‘Abdullah—meaning Ibn Mas’ud—and said: "What is your opinion regarding a man who married a woman?"—then he mentioned the hadith. He said: A man from Ashja’ said—Mansur said: I believe it was Salamah ibn Yazid—"The Messenger of Allah (ﷺ) judged in a case like this: A man from among us married a woman from Banu Ru’as, who was called Birwa’ bint Washiq. He then went out on a journey and fell into a well, and he became old [or: he stayed for a long time], and he died without having set a dowry for her. They came to the Messenger of Allah (ﷺ), and he said: 'She shall have a dowry like that of the women of her status, neither less nor more, and she shall have the inheritance, and she must observe the waiting period ('iddah).'"