“Once, when I was present, a man said to abu ‘Abd Allah (a.s.), ‘I pray to Allah to keep my soul in service for your cause, I make a great number of mistakes in my Salah (prayer).’ He (the Imam) said, ‘Has anyone remained safe thereby?’ I (the narrator) then said, ‘I think no one makes as many mistakes as I do.’ Abu ‘Abd Allah (a.s.), then said to him, ‘O abu Muhammad, sometimes of Salah (prayer) of a servant (of Allah) one-third is raised, sometimes one-half or three- fourth or less or more depending upon the quantity of one’s mistakes in that Salah (prayer). However, it is completed with his optional Salah (prayer).’ Abu Basir then said to him (the Imam), ‘I think, optional Salah (prayer) should not be omitted in any condition.’ Abu ‘Abd Allah (a.s.), then said, ‘Yes, it should not be omitted.’”