The Messenger of Allah ﷺ said to me, "Your permission to enter upon me is that you may lift the curtain and listen to my private conversation until I tell you to stop."
حدثنا علي بن محمد حدثنا عبد الله بن إدريس عن الحسن بن عبيد الله عن إبراهيم بن سويد عن عبد الرحمن بن يزيد
قال لي رسول الله ﷺ إذنك علي أن ترفع الحجاب وأن تسمع سوادي حتى أنهاك
[Sahih] Reported by Muslim, Book of Greetings, Chapter on the permissibility of using the removal of a curtain or other signs as permission to enter, hadith no. 2169, from the hadith of Abdullah bin Idris and others, with the same wording.