It is narrated that after the Holy Prophet ‎ﷺ left the world, Madīnah faced severe drought and famine. The people of the city came to Sayyidah 'Ā'ishah seeking help and advice so she instructed them to make an opening above the grave of the Messenger of Allāh ﷺ so there would be no barrier between him and the sky. As soon as they did this, it immediately began to rain until all the plants grew and the animals became extremely healthy, and the city rejoiced. [Al-Dārimī]

The Ottomans later placed a specific tile on the Dome to commemorate this event as you can see on the picture below where he ‎ﷺ is resting. (Look at this picture