Asma bint Yazid (May Allah be pleased with her) reported:
The Prophet (ﷺ) passed by us when we were with a party of women, and he greeted us with salam.[Abu Dawud and At-Tirmidhi who classified it as Hasan]. This is the wording of Abu Dawud.
In At-Tirmidhi: 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.