Sunan Ibn Majah, Chapter: Chapters Regarding Funerals

"I could not find him, meaning The Prophet (saw), and he was in Al-Baqi'. He said: "As-salamu 'alaykum dara qawmin mu'minin. Antum lana faratun wa inna bikum lahiqun. Allahumma la tahrimna ajrahum wa la taftinna ba'dahum. (Peace be upon you, O abode of believing people. You have gone ahead of us and verily we will join you soon. O Allah, do not deprive us of their reward and do not put us to trial after them)." Sahih