Sahih Muslim Book 40, Hadith Number 6788.
Chapter : The inmates of paradise would see the inmates of the upper apartment as are seen the planets in the sky.
Sahl b. Sa’d reported Allah’s Messenger (may peace be upon him) as saying: The inmates of Paradise will look to the upper apartment of Paradise as you see the planets in the sky. I narrated this hadith to Nu’man b. Abi ‘Ayyash and he said: I heard Abu Sa’id al-Khudri as saying: As you see the shining planets in the eastern and western (sides of) horizon.