Muhammad bin Ja'far bin Abi Kathir محمد بن جعفر بن أبي كثير · Chapters on Seeking Permission

that the Messenger of Allah (ﷺ) passed through the Masjid one day, and a group of women were sitting, so he motioned his hand with the Salam - 'Abdul-Hamid (one of the narrators) gestured with his hand.