Is it prescribed to conclude a lecture with the last verses of Surat al-Saffat?

Question:
May Allah reward you. Abu Rayan, in one of his questions, says: Honorable Shaykh, at the end of the gathering, the lecturer says and then the attendees repeat these phrases. Is this established?

Answer:
The conclusion of a gathering is what is reported from the Prophet (peace and blessings be upon him) that he said: The expiation of the gathering, when one intends to stand up, is to say This is the expiation of the gathering. As for a lecture or a lesson, if it is concluded with "Glorified and Exalted is He," or if it is concluded with supplication, there is nothing wrong with that, and the attendees say "Ameen" to the supplication; because people are in need of that, , or if it is concluded with something else, there is nothing wrong with that.