Al-Husayn ibn Said, from Ibn Sinan, from a man, from Abu Abdillah عليه السلام, peace be upon him:
Imam عليه السلام said: “Breaking the fast upon water washes away the sins of the heart.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 4, p. 264