It was narrated that 'Aishah said that

every time it was her night for the Messenger of Allah (ﷺ) to stay with her, he would go out at the end of the night to Al-Baqi' and say: "As-salamu 'alaykum dara qawmin mu'minin, wa inna wa iyyakum mutawa'idun ghadan wa mutawakilun, wa inna in sha' Allahu bikum lahiqun. Allahummaghfir li ahli baqi'il gharaqad. (Peace be upon you, O abode of believing people. You and we used to remind one another about the Day of Resurrection and we are relying on one another (with regard to intercession and bearing witness). Soon we will join you, if Allah willing. O Allah, forgive the people of Baqi' Al-Charqad.)"