Abu Dawud and An-Nasa'i narrated on the authority of Ibn 'Abbas that 'Umar (RAA) asked about the judgment of the Prophet (ﷺ) concerning the Diyah of the dead fetus. Hamal bin An-Nabighah Al-Hudhaili then got up and said, "I was between the two women. One of them struck the other with a stone, killing her and what was in her womb. So the Messenger of Allah (ﷺ) ordained...." (as above). Ibn Hibban and al-Hakim graded it as Sahih.