The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1375
'Abdullah (b. Mas'ud) reported: I have seen the time when no one stayed away from prayer except a hypocrite, whose hypocrisy was well known, or a sick man, but it a sick man could walk between two persons (i. e. with the help of two persons with one on each side) he would come to prayer. And (further) said: The Messenger of Allah (may peace be upon him) taught us the paths of right guidance. among which is prayer in the mosque in which the Adzan is called.