Hadith 4:620
Muhammad ibn Bakr narrated to us, from Ibn Jurayj, who said: A person said to 'Ata', "I performed *istinthar* (clearing the nose with water), and the water entered my throat." He said, "There is no harm, as long as you did not intend it."
حدثنا محمد بن بكر عن بن جريج قال إنسان لعطاء استنثر فدخل الماء حلقي قال لا بأس ما لم تملك