It is narrated from Alqamah bin Qays that some people came to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) and said: "A man among us married a woman but did not fix a dowry for her, and he died before the marriage was consummated (what is the ruling on this?)." Abdullah bin Mas'ud (may Allah be pleased with him) said to them: "Since I parted from the Messenger of Allah (peace and blessings be upon him), I have not been asked a question harder for me than this; go to someone else." The narrator says: They kept coming to him about it for a month, then finally they said: "If we do not ask you, whom shall we ask, when you are the most trusted pillar of the Companions of Muhammad (peace and blessings be upon him) in this city?" So he said: "I will give my opinion on this matter with my utmost effort of reasoning (ijtihad). If it is correct, it is from Allah alone, who has no partner; and if it is wrong, it is from me, and Allah and His Messenger are free of it. My opinion is that she should have a dowry like the dowry of the women of her family (mahr al-mithl), with neither decrease nor excess; she will also receive a share of the inheritance, and she must observe a waiting period ('iddah) of four months and ten days." The narrator says: Some people of the tribe of Ashja' were present there; they stood up and said: "We bear witness that you have given exactly the same judgement as the Messenger of Allah (peace and blessings be upon him) gave concerning a woman of ours, Barwa' bint Washiq." The narrator says: Abdullah bin Mas'ud (may Allah be pleased with him) was never seen as happy about anything, after his acceptance of Islam, as he was that day. Then he said (out of humility): "O Allah, if this judgement is correct, it is from You alone; and if it is wrong, it is from me and from Satan, and Allah and His Messenger are free of it." This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Abu Abdullah Muhammad bin Ya'qub al-Hafiz that he heard this statement of Imam al-Shafi'i (may Allah have mercy on him): "If the hadith of Barwa' bint Washiq is proven authentic, I will adopt it as my position." Abu Abdullah said: "Had I been in the time of Imam al-Shafi'i (may Allah be pleased with him), I would have stood before his students and said: 'This hadith has indeed been proven authentic, so now adopt the position according to it.'" Imam al-Hakim says: Imam al-Shafi'i withheld judgement on its authenticity because, although this narration was sound, the verdict was that of Abdullah bin Mas'ud, and (at that time) the chain went back to some unknown people of the tribe of Ashja'; whereas our Shaykh Abu Abdullah ruled it authentic because a trustworthy narrator explicitly named a reliable Companion in it, namely Ma'qil bin Sinan al-Ashja'i (may Allah be pleased with him). What I have mentioned is supported by the following:

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), concerning a man who married a woman and died before consummating the marriage with her and before fixing a dowry, that he said: "She is entitled to the full dowry (mahr al-mithl), she must observe the waiting period ('iddah), and she is entitled to inheritance." Then Sayyiduna Ma'qil bin Sinan (may Allah be pleased with him) stood up and said: "I bear witness that the Messenger of Allah (peace and blessings be upon him) gave this very judgement concerning Barwa' bint Washiq." Thus this hadith became sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim).