5-40 Muhammad ibn al-Hassan - may God be pleased with him - narrated that Muhammad ibn al-Hassan al-Saffar quoted Ahmad ibn Aba Abdullah al-Barqy, on the authority of his father Muhammad ibn Khalid who linked it up through a chain of narrators to Aba Abdullah as-Sadiq (MGB),

“Five things will break one’s fast: to eat; to drink; to have sexual intercourse; to submerge the whole body in water; and to ascribe lies to God, His Prophet (MGB) and the Immaculate Imams (MGB).”