It is narrated from Hazrat Ibn Absa (may Allah be pleased with him) that I saw the Prophet (peace and blessings of Allah be upon him) rinsing his mouth and cleaning his nose during Ramadan.
Hadith Referenceمسند احمد / مسند الشاميين / 17017
Hadith Gradingحکم دارالسلام:إسناده ضعيف لانقطاعه، كثير بن زياد لم يدرك عمرو بن عبسة