What is zamzam?

The water of Zamzam is water of great virtue which first sprang forth when Jibreel (peace be upon him) struck (the earth) with his wing (Saheeh al-Bukhaari, 3364). Allaah provided water for Ismaa'eel (peace be upon him) and his mother with it. The heart of the Prophet (peace and blessings of Allaah be upon him) was washed with Zamzam water. Many saheeh ahaadeeth have been narrated concerning its virtues, such as: The Prophet (peace and blessings of Allaah be upon him) said: "The best water on the face of the earth is the water of Zamzam;it is a kind of food and a healing from sickness." (Saheeh al-Jaami', 3302). 

According to Islamic belief, zamzam is a miraculously-generated source of water from God, which began thousands of years ago when Abraham's infant son Ishmael was thirsty and crying for water and discovered a well by kicking the ground. Millions of pilgrims visit the well each year while performing the Hajj or Umrah pilgrimages, in order to drink its water.