Abu Dawud said: Likewise, it was narrated by al-Hakam, from Mujahid, from al-Mughirah.

4570 — ‘Uthman ibn Abi Shaybah and Harun ibn ‘Abbad al-Azdi narrated to us — the meaning [being the same] — they said: Waki‘ narrated to us, from Hisham, from ‘Urwah, from al-Miswar ibn Makhramah: That ‘Umar consulted the people regarding a woman’s miscarriage [imlas]. Al-Mughirah ibn Shu‘bah said: “I witnessed the Messenger of Allah ﷺ rule concerning it with a ghurrah: a male or female slave.” He said: “Bring me someone who will bear witness with you.” So he brought Muhammad ibn Maslamah — Harun added: — and he bore witness for him. Meaning: a man striking the belly of his wife.

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And it was also recorded by Muslim (1682), and al-Nasa’i in al-Kubra (6997) via the route of Jarir ibn ‘Abd al-Hamid, with this chain of transmission.
See what precedes it.

(1) A sound hadith, but Waki‘ — who is Ibn al-Jarrah — erred in mentioning al-Miswar ibn Makhramah in its chain. Ibn al-Madini said, as found in al-Nukat al-Ziraf by Ibn Hajar (11511): “I do not think Waki‘ was anything but mistaken in his saying: al-Miswar ibn Makhramah.” And al-Daraqutni said in al-Tatabbu‘, p. 219: “This is an error.”
It was also recorded by Muslim (1683), and Ibn Majah (2640) via the route of Waki‘ ibn al-Jarrah, with this chain of transmission.
And it was recorded by al-Bukhari (6907) from ‘Ubayd Allah ibn Musa, from Hisham ibn ‘Urwah, from his father, that ‘Umar adjured the people… And ‘Urwah ibn al-Zubayr — although he did not reach the time of ‘Umar ibn al-Khattab — heard this report from al-Mughirah ibn Shu‘bah, as clarified by the narration of Wuhaib ibn Khalid that follows with the author afterward, and a group agreed with him on that.
It is in Musnad Ahmad (18213).
See the two preceding routes before it.
See what follows it.

Imlas of a woman: her miscarrying the child. It is said: amlasat al-mar’ah, meaning she gave birth to her child before its time. And everything that slips from the hand has malisa malasan, and amlasa also [is used] — two dialects.