The virtuous scholar, jurist Abu Ja'far Muhammad ibn Ali ibn al-Hussain ibn Musa ibn Babawayh al-Qummi, the author of this book, may God have mercy on him, said: "Indeed, Allah سبحانه وتعالى, Blessed and Exalted, says: 'And We sent down from the sky pure water' (Surah Al Furqan 25:48). And He, Mighty and Majestic, says: 'And We sent down from the sky water in due measure, and We settled it in the earth, and indeed We are able to take it away' (Surah Al Mu'minun 23:18). And He, Mighty and Majestic, says: 'And He sent down upon you water from the sky to purify you with it' (Surah Al-Anfal 8:11). Therefore, all water originates from the sky, and all of it is purifying. Sea water is pure, and well water is pure."