Amir al-Mu’minin `Ali b. Abi Talib (as) said: In Paradise there is a tree with gems that come out of the top and black-and-white winged horses that come out of the bottom. The horses do not defecate, nor do they urinate. The friends of Allah will ride them, and by them, they will fly wherever they want in Paradise. Those lower than them will say: “O our Lord! How did Your servants attain this nobility?” So, Allah will say: “They would pray in the night and not sleep, and they would fast in the day and not eat, and they would fight the enemies without cowardice, and they would give in charity without stinginess.”