18. Abu Ali al-Ash‘ariy has narrated from Muhammad ibn ‘Abd al-Jabbar from Safwan from Sayf al-Tammar who has said the following: “I once asked abu ‘ Abd Allah , about the case of a man who says to his wife, ‘You are like the back of my sister, maternal or paternal aunt.’ He (the Imam) said, ‘Allah has mentioned the mothers, this certainly is unlawful. ’”