Hadith 1126
Abdullah bin 'Umar (RA) reported that the day of 'Ashura was mentioned before the Apostle of Allah (ﷺ) and he narrated a hadith like one (narrated above).
Hadith 2099
Jabir bin'Abdullah (RA) reported Allah's Messenger (ﷺ) as saying: None of you should lie on his back and place one of his feet upon the other.