Abdul Rahman reported that 'Ali, while delivering the address said: O people, impose the prescribed punishment upon your slaves, those who are married and those not married, for a slave-woman belonging to Allah's Messenger (ﷺ) had committed adultery, and he committed me to flog her. But she had recently given birth to a child and I was afraid that if I flogged her I might kill her. So I mentioned that to Allah's Apostle (ﷺ) and he said: You have done well.
This hadith has been narrated on the authority of as-Suddi with the same chain of transmitters, but he did not mention: "Those who are married and those who are not married." There is also an addition in it: "I spare her until she is all right."
´Narrated Abu 'Abdur-Rahman As-Sulami:` "Ali gave a Khutbah, and said: 'O people, establish the penalties upon your slaves, those married from them and those unmarried. A slave girl of the Prophet (ﷺ) committed illegal sexual intercourse so he ordered me to whip her. I went to her and she was just experiencing her post-natal bleeding, so I feared that if I were to whip her I would kill her' - or he said: 'She would die' - 'so I went to the Messenger of Allah (ﷺ) and I told that to him. So he said: 'You did well.'"
Shaykh Dr. Abdur Rahman Freywai
Explanation: 1: That is, she had given birth only a few days before this.
2: This doubt is from the narrator.
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 1441