To what extent is the circulating story valid concerning Aws and his wife Khawla, regarding the dialogue that took place between them about prayer and the marital relationship, which concluded with his saying to her, "You are to me as the back of my mother"?

The summary of the answer: The mentioned report has been rephrased and was not conveyed exactly as narrated in the books of Hadith, but it is well-known and recognized as the reason for the revelation of the verse of Zihar. A narration from Al-Bayhaqi states that Aws ibn Al-Samit called his wife while she was praying, but its chain of transmission is weak due to the presence of a mudallis (one who conceals) who did not explicitly state hearing the Hadith, and it also contains a narrator about whom Al-Bukhari said: "There is doubt concerning his authenticity." The famous narration is the one transmitted by Imam Ahmad and Abu Dawud from Khawla bint Tha'laba, detailing her husband Aws ibn Al-Samit's zihar against her, her complaint to the Prophet (peace be upon him), and the revelation of the beginning of Surat Al-Mujadila because of it. This chain of transmission contains a narrator whose status is unknown. The report as a whole is authentic due to supporting evidence, and Sheikh Al-Albani authenticated it. Among its supporting evidence is the Hadith of Aisha (may Allah be pleased with her), narrated by Ibn Majah and Al-Hakim, and its origin is in Al-Bukhari and Al-Nasa'i, where she heard part of Khawla's complaint and the revelation of the verses.