“I once asked abu al-Hassan (a.s.), about my performing Tawaf in which after the fourth round of walking around the House I became tired: if I could perform its two Rak‘at Salat (prayer) in a sitting position. He (the Imam) said, ‘No, you cannot do so.’ I then asked, ‘What should a person do in such case while in Salat (prayer) of night. In this case if one feels weakness, it is permissible to perform them in sitting position, and in this case it is not permissible.’ He (the Imam) said, ‘Is it right to perform Tawaf and you are sitting?’ I replied, ‘No, it is not right.’ He (the Imam) then said, ‘Perform Salat (prayer) while you are standing.’”