It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that once he saw in a dream that he was writing Surah Sad. When he reached the verse of prostration, he saw that the inkwell, pen, and everything that was present there all fell into prostration. Upon waking up, he related this dream to the Prophet (peace and blessings be upon him), and after that, the Prophet (peace and blessings be upon him) always performed the prostration of recitation in it.