Al-Kāfi
Hadith 994وَ بِإِسْنَادِهِ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ قَالَ رَسُولُ اللَّهِ ( صلى الله عليه وآله ) إِذَا تَجَشَّأْتُمْ فَلَا تَرْفَعُوا جُشَاءَكُمْ .
6. Through the same chain of narrators as that of the previous Hadith the following is narrated: ‘Abu ‘Abd Allah (a.s.), has said that the Messenger of Allah, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, has said, ‘When you belch then do not make it loud.’”