Ablution (wudu) when a woman touches her private part

Busrah bint Safwan al-Asadiyyah (may Allah be pleased with her) heard the Prophet (peace and blessings be upon him): he (peace and blessings be upon him) "used to order ablution after touching the private part, and a woman will do the same."
(b) Abu Ahmad bin Adi (may Allah have mercy on him) said: This addition in the text of the hadith, "and a woman likewise," is narrated from Imam al-Zuhri by no one except Ibn Namir.

Sayyiduna Urwah bin al-Zubayr (may Allah have mercy on him) said: During his governorship in Madinah, Marwan bin al-Hakam wrote that ablution should be performed after touching the private part when one's hand touches it. I objected to this and said: There is no ablution upon one who touches the private part. Marwan said: Sayyidah Busrah bint Safwan (may Allah be pleased with her) informed me that she heard from the Messenger of Allah (peace and blessings be upon him); it was mentioned before him (peace and blessings be upon him) what ablution is to be performed for, and the Messenger of Allah (peace and blessings be upon him) said: "Ablution is to be performed after touching the private part." Urwah (may Allah have mercy on him) said: I kept arguing with Marwan until a guard was sent to Sayyidah Busrah (may Allah be pleased with her) to ask her what she narrated about this, and Sayyidah Busrah (may Allah be pleased with her) wrote back to them the same thing that Marwan had narrated to me.
This is the authentic version of al-Zuhri's hadith.

Abd al-Rahman bin Namir said: I asked Imam al-Zuhri about a woman touching her private part: must she perform ablution? He said: Abdullah bin Abi Bakr narrated to me, from Urwah, from Marwan bin al-Hakam, the narration of Busrah bint Safwan (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) said: "When anyone's hand touches his private part, let him perform ablution," and a woman will do the same.
(b) The apparent meaning of this hadith shows that "and a woman likewise" is the saying of al-Zuhri.
What also indicates this is that all the other narrators narrated it from al-Zuhri without this addition. It was also narrated in the hadith of Isma'il bin Ayyash from Hisham bin Urwah from his father, but it is not mahfuz (preserved).

Shu'ayb narrates from his grandfather that the Messenger of Allah (peace and blessings be upon him) said: "Whichever man touches his private part, let him perform ablution, and whichever woman touches her private part, let her also perform ablution."
Muhammad bin al-Walid al-Zubaydi is thiqah (trustworthy).

Amr bin Shu'ayb narrates from his grandfather (may Allah be pleased with him), with the same chain, a narration of the same meaning.
(b) Abu Ahmad said: The hadith of Ibn Thawban from his father from Amr is gharib. (c) The Shaykh said: Al-Muthanna bin al-Sabbah differed from them in its chain from Amr, and he is not strong.

Sayyidah Busrah bint Safwan (may Allah be pleased with her), who was from Banu Kinanah, said: I said: O Messenger of Allah, what do you say about one of us women who touches her private part, or a man who touches his private part after performing ablution? He (peace and blessings be upon him) said: "O Busrah bint Safwan, she should perform ablution."
Sa'id bin al-Musayyib (may Allah have mercy on him) said that Marwan sent a man to her to ask her, and she said: Leave me alone; I asked the Messenger of Allah (peace and blessings be upon him) while so-and-so and so-and-so and Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) were with him (peace and blessings be upon him), and he (peace and blessings be upon him) ordered me to perform ablution.

It is narrated from Sayyidah Aishah (may Allah be pleased with her): "When a woman touches her private part, she should perform ablution."