I saw Abal Ḥasan (Imam Riďā (a.s.)) bidding farewell (to the Messenger of Allāh (s.a.a.w.)) when he wanted to go for ‘Umrah. It was after sunset when he approached the grave of the Messenger of Allāh (s.a.a.w.) from the direction of the head. He said Salām to the Messenger of Allāh (s.a.a.w.) and clung to the grave. Then he came to the pulpit of the Messenger of Allāh (s.a.a.w.). Thereafter, he moved back to the grave and established prayers (so close to the grave that) his left shoulder touched the part of the grave which is close to a pillar. This pillar is situated on the opposite side of (another) pillar which is by the head of the Prophet (s.a.a.w.). He prayed six or eight Rak’ah while wearing his sandals and the length of his RUKŪ’ and SUJŪD was as long as reciting TASBǏḤĀT three or more times. After he finished his prayers, he prostrated for such a long time that the sand (on which he had prostrated) became moistened from his sweat. And some of our companions added that he was seen placing his cheek on the ground of the Mosque.