A reliable tradition states that in this world and the world-to-come, there is nothing better than water. Anyone who takes pleasure in drinking water will take pleasure when God gives him the wine of Heaven.
According to a tradition from Hazrat Ali (a.s.), Zamzam water is the best water among all the waters of the earth and Burhoot water(which is in Yemen) is the worst for it is haunted by the spirits of the nonbelievers (Kafirs), and day and night it is in a state of curse.
According to Imam Ja’far-e-Sadiq (a.s.), Zamzam water is a cure for all diseases.
Hazrat Ali (a.s.) said that one should drink rain water as it purifies the body and cures all pains and diseases.
According to Imam Ja’far-e-Sadiq (a.s.), cold water lessens temperature, cures vomiting, digests food, and is an antidote for heat and also stated that boiled water is good for all types of pains and is not harmful in any way.
According to Imam Reza (a.s.), the water which is boiled seven times in seven different vessels cures fever and cough.
Ibne Abi Taifur, a doctor, states that when he visited Imam Moosa Kazim (a.s.), he saw him drinking a lot of water. When he stopped, the Imam (a.s.) replied that drinking water even in excess is not harmful in any way as it digests food in the stomach, lessens excitement (anger), increases intellect and cures vomiting.