Narrated by Ahmad ibn Muhammad, from Ali ibn al-Hakam, from Saif ibn Umayrah, from Abu Bakr al-Hadrami, from Abu Abdullah عليه السلام, who said:
Imam عليه السلام said: "You are not required to rinse your mouth (madmadah) or sniff water into your nose (istinshaq), as they are considered part of the inner body (al-jawf)."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 138