Musnad Abu Ya'la al-Mawsili 152:289

Abu Khaythama narrated to us, Mu'awiyah narrated to us, Za'idah narrated to us, he said: Sulayman heard them mentioning from Ibrahim ibn Suwayd, from Alqamah, from Abdullah, who said: The Prophet (peace and blessings of Allah be upon him) said: "Your permission to enter upon me is that you lift the curtain."