Al-Kāfi

4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ahmad ibn al-Hassan from ‘Amr ibn Sa‘id from Musaddiq ibn Sadaqah from ‘Ammar ibn Musa who has said the following: “I once asked abu ‘Abd Allah (a.s.), about the case of a man with whose burping something comes up to his throat and then it goes back when he is fasting. He (the Imam) said, ‘He is not obligated for anything .’”