The Messenger of Allah ﷺ led us in the afternoon prayer at Mukhammas, then said, "This prayer was presented to those who came before you, but they neglected it. Whoever preserves it will have his reward twice over. There is no prayer after it until the witness rises," and the witness is the star.
صلى بنا رسول الله ﷺ العصر بالمخمص فقال: إن هذه الصلاة عرضت على من كان قبلكم فضيعوها. فمن حافظ عليها كان له أجره مرتين. ولا صلاة بعدها حتى يطلع الشاهد والشاهد النجم.