Asma' bint Yazid (May Allah be pleased with her) reported:
The Messenger of Allah (ﷺ) passed through the mosque one day and there was a group of women (about ten of them) sitting in the mosque. He raised his hand to offer greetings.[At- Tirmidhi].
App reference: Book 6, Hadith 11
Arabic/English book reference: Book 6, Hadith 855