There is a door in Paradise called Rayyan. Only those who observe fasting can enter that door on doomsday, nobody else can enter with them.
Then, a voice is heard ‘Where are the ones who observed fasting in the world?’ They come and enter paradise from that door. When the last one of them enters, the door is closed; nobody else is permitted after that. Whoever enters Paradise from that door never gets thirsty again eternally"(Bukhari, Sawm: 4, Bad ul Halk: 9; Muslim, Siyam: 166; Tirmidhi, Sawm: 55)