The Messenger of Allah ﷺ forbade sadl, meaning during the prayer.
حدثنا أبو سعيد حدثنا وهيب وحماد عن عسل عن عطاء
نهى رسول الله ﷺ عن السدل يعني في الصلاة
No references are available.
Its isnad is daif, due to the weakness of Asl bin Sufyan.Suyuti related a hadith in Jami Saghir with wording that the Messenger of Allah forbade sadl in prayer, and that a man cover his mouth. It was related by Abu Dawud, Tirmidhi, Nasai, Ibn Majah, and Hakim from Abu Hurairah, and Suyuti noted its being sahih.