What is the purpose of repeatedly reciting Al-Fatihah over water for healing? And is it a condition to use Zamzam water or for the reciter to have strong faith? And is this method beneficial for all diseases?

What Imam Ibn al-Qayyim intended by repeated recitation is its abundance, not limiting it to a specific number. It is also not a condition that the recitation be over Zamzam water, for the Qur’an is a healing for every physical and spiritual ailment. The stronger a servant’s faith and conviction, the greater the benefit they derive from the Qur’an.