Muhammad bin Ja'far said:

What if a man gets married without naming the mahr, then he dies? Sa'eed narrated from Qatadah from Khilas and Abu Hassan al-A'raj from 'Abdullah bin ‘Utbah bin Mas'ood that he said. They kept going to Ibn Mas'ood (and asking this question) for a month or thereabouts, and they said: You have to give an answer concerning this matter. He said: I will give a verdict: she is entitled to a dowry like that of her peers, not much more and not much less, she has the right of inheritance and she has to observe the 'iddah. If it is correct, then it is from Allah, may He be glorified and exalted; if it is wrong, then it is from me and the Shaitan, and Allah, may He be glorified and exalted, and His Messenger are innocent of it. Some men of Ashja', among whom were al-Jarrah and Abu Sinan, stood up and said: We bear witness that the Messenger of Allah (ﷺ) issued a verdict like this concerning one of our women whose name was Barwa’ bint Washiq. Ibn Masood rejoiced greatly at that because his verdict was in accordance with the verdict of the Messenger of Allah (ﷺ).